# P&ID symbols → components

Generated from `registry/pid/pid.json`. Every symbol drawing is at `https://deck-twin-library.demoareeb.workers.dev/symbols/<file>`, and the whole legend is one image at https://deck-twin-library.demoareeb.workers.dev/symbols/legend.svg. Use it side by side with the P&ID.

## How to read a sheet

1. **Find the legend.** Read the drawing's own legend or "symbols & abbreviations" sheet first. Company legends override the defaults here.
2. **Tile large drawings.** Split big scans so tags are legible: `python3 -I scripts/tile.py <sheet.png> --grid 3x2 --scale 2`.
3. **Read equipment first.** Match each equipment symbol and its tag letters (V, P, K, E, T…) to a component below. Confirm with the tag; the tag letter beats symbol shape when they disagree.
4. **Read the lines.** For each line, record the line number (`8"-PG-2101-D6A-N` → size, service, class, insulation), its two end nozzles, and every valve or inline item along it, in flow order.
5. **Read the instruments.** ISA 5.1 bubbles only become components when they are field devices on the pipe or vessel. A bubble with a line through it is in the DCS (control room) and is not physical.
6. **Read the datasheets.** For each item, the datasheet fields listed below map straight onto props.

| Component | Drawn as | Tag / ISA | Datasheet → props |
|---|---|---|---|
| `mud-pump` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/mud-pump.svg) | Reciprocating pump symbol (circle with a piston and crank) on the mud system flow sheet, with a pulsation dampener (small dome) on the discharge going to the standpipe manifold and suction from the mud tanks; usually two or three pumps in parallel. *The dampener dome and the mud / standpipe service distinguish it from a process plunger pump (reciprocating-pump). Only on drilling flow sheets.* | MP, P | Mud pump datasheet (API 7K): Number of cylinders → `cylinders`; Input power → `kw`; Drive type → `drive`; Suction size → `suctionNps`; Discharge size → `dischargeNps`; Tag number → `tag` |
| `choke-manifold` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/choke-manifold.svg) | From the BOP choke line: two gate valves into a cross or header, then parallel branches each with a gate valve and a choke (bow-tie with a diagonal arrow), rejoining to the mud-gas separator or flare; a straight-through bleed line in the middle on many manifolds. *Production chokes on a tree are single valves; a choke manifold has several parallel choke branches with block valves. Only on well-control schematics.* | HCV, PV, PI, PT | Choke and kill manifold datasheet (API 16C): Rated working pressure → `psi`; Bore → `bore`; Remote (hydraulic) chokes → `remoteChokes`; Manual chokes → `manualChokes`; Tag number → `tag` |
| `shale-shaker` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/shale-shaker.svg) | A box with a sloping dashed screen deck: returns from the flowline enter one end, cuttings leave off the low end of the screen, and the cleaned mud drops through to the tank below; vibrator motors drawn on the basket. *Dashed sloping screen = shaker. Desanders and desilters on the mud system are cyclones (cones); a degasser is a vessel.* |  | Shale shaker datasheet (API RP 13C screens): Screen panels → `panels`; Decks → `decks`; Deck angle → `deckAngle`; Feed size → `feedNps`; Tag number → `tag` |
| `mud-tank` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/mud-tank.svg) | An open-topped rectangular tank divided into compartments, each with an agitator (motor M on a shaft with impeller blades) and the mud level dashed; suction to the mud pumps and returns from the shakers. *Open top plus agitators = mud pit. A closed process vessel is drawn as a capsule. Pit volume totaliser (PVT) level transmitters sit on each compartment. ISA codes here: LT = pit volume.* | T, LT, LI | Mud tank datasheet (API RP 13C): Length → `length`; Width → `width`; Height → `height`; Compartments → `compartments`; Agitator motor power → `agitatorKw`; Suction size → `suctionNps`; Return size → `returnNps`; Tag number → `tag` |
| `plet` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/plet.svg) | On subsea P&IDs: the pipeline ending at a structure (dashed boundary) with an isolation valve and a connection hub (clamp or collet connector, drawn as a pair of thick bars or a hub outline) for the spool or jumper; on field layouts a small rectangle at the pipeline end. *A PLEM is the same idea with several hubs or a manifold header. Topsides pig traps and risers are separate items.* | PLET, PLEM | Subsea structure datasheet (API 17P / API 17D): Pipeline size → `nps`; Flange rating → `rating`; Hub orientation → `hubOrientation`; Hub cap → `hubCap`; Tag number → `tag` |
| `subsea-manifold` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/subsea-manifold.svg) | Subsea P&ID: a dashed structure boundary containing production and test headers with each well slot (jumper hub) branching to both headers through its own subsea valves, and header outlets to the flowlines; on field layouts a rectangle with the wells radiating to it. *Same branching logic as a topsides production-manifold, but inside a subsea structure boundary with hubs instead of flanges. A single-hub structure at a pipeline end is a PLET.* | SM, MF | Subsea manifold datasheet (API 17P / API 17D): Number of well slots → `slots`; Slot (jumper) size → `slotNps`; Header size → `headerNps`; Flange rating → `rating`; Tag number → `tag` |
| `umbilical-termination-assembly` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/umbilical-termination-assembly.svg) | On subsea control schematics: the umbilical (a thick double line or bundle) ending at a termination head inside a dashed structure, fanning out to hydraulic, chemical and electrical couplers that connect by flying leads to trees and manifolds. *A structure where the umbilical bundle splits into many small hydraulic / electrical lines is a UTA or SUTU; one carrying production pipework is a manifold or PLET.* | UTA, SUTU | Umbilical termination datasheet (API 17E / ISO 13628-5): Umbilical outside diameter → `umbilicalOd`; Hydraulic / chemical couplers → `couplers`; Electrical connectors → `electrical`; Tag number → `tag` |
| `subsea-tree` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/subsea-tree.svg) | Same valve stack as a surface tree, but every valve is actuated (small actuator boxes), it sits inside a dashed subsea boundary above the seabed line, and an annulus line and SCSSV control line run alongside. Production master (PMV), production wing (PWV) and the subsea choke sit on the side outlet to the flowline or jumper. *A dashed subsea boundary, seabed line and all-actuated valves distinguish it from a surface christmas-tree. PMV / PWV / AMV / AWV are subsea valve tags, not ISA letter codes.* | XT, SXT, W, XV, PT, TT | Subsea tree datasheet (API 17D / ISO 13628-4): Production outlet size → `productionNps`; Annulus outlet size → `annulusNps`; Subsea choke → `choke`; Tag number → `tag` |
| `pipe-handling-catwalk` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/pipe-handling-catwalk.svg) | Drill-floor and pipe-deck layouts: a long rectangle with the trough centreline aimed at the V-door, pipe racks drawn as parallel lines along both sides, and an arrow towards the drill floor. *Only on drilling layouts, never on P&IDs.* | CW | Pipe-handling equipment datasheet (API 7K): Catwalk length → `length`; Drill floor height → `floorHeight`; Maximum pipe OD → `pipeOd`; Tag number → `tag` |
| `cement-unit` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/cement-unit.svg) | On well-service schematics: a dash-dot skid boundary with displacement / mixing tanks and two reciprocating (triplex) pump symbols discharging into a common high-pressure line to the cement head or standpipe. *Twin reciprocating pumps on a skid with displacement tanks = cement unit; a single mud pump with a dampener is a mud-pump. Usually on temporary well-service layouts rather than process P&IDs.* | CU, X | Cementing unit datasheet (API 7K pumps, DNV 2.7-3 skid): Pump driver power → `kw`; Displacement tank capacity → `tankBbl`; Discharge rating → `dischargeRating`; Tag number → `tag` |
| `coiled-tubing-unit` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/coiled-tubing-unit.svg) | Well-intervention layouts: a reel (two concentric circles) with the tubing running over the gooseneck to the injector head (box) above the well-control stack on the well; the control cabin and power pack are rectangles beside the reel. *Temporary equipment, not shown on process P&IDs. The stack below the injector is a well-control item (bop-stack).* | CTU | Coiled tubing equipment datasheet (API RP 16ST, API 5ST tubing): Tubing OD → `tubingOd`; Reel flange diameter → `flangeDia`; Reel core diameter → `coreDia`; Tag number → `tag` |
| `transformer` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/transformer.svg) | Two overlapping circles (one per winding) on the single-line diagram, with the HV feeder above and the LV feeder below. Winding symbols (Δ, Y, Yn) and the MVA / kV rating are written beside it; a diagonal arrow through both circles marks an on-load tap changer. *Two circles = two-winding transformer; three circles = three-winding. ANSI drawings show two facing coils instead. Two circles in a P&ID instrument context are not used, so this symbol is almost always electrical.* | TR, TX | Transformer datasheet / rating plate (IEC 60076-1): Rated power → `mva`; HV rated voltage → `hvKv`; LV rated voltage → `lvKv`; Cooling (ONAN / ONAF) → `cooling`; Terminations → `terminations`; On-load tap changer → `oltc`; Tag number → `tag` |
| `switchgear` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/switchgear.svg) | Thick horizontal busbar with an incoming feeder and several outgoing feeders, each through a circuit breaker (a switch blade with a small × on the fixed contact) or contactor, often inside a dashed boundary with the board tag and voltage. *Breaker: × on the contact. Disconnector: a bar across the contact. Contactor (MCC starter): a half-circle on the contact. On layouts a switchgear line-up is a long rectangle divided into panels inside an E-house.* | SWG, MCC | Switchgear / switchboard datasheet (IEC 62271-200 / IEC 61439): Type (MV / LV / MCC) → `kind`; Number of panels → `panels`; Rated voltage → `kv`; Tag number → `tag` |
| `e-house` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/e-house.svg) | Rectangle with door swings (quarter arcs at the openings) on the layout, labelled with the building tag (LER, E-house, MCC room). On a P&ID it appears only as a dashed boundary or an off-sheet reference. *All buildings look alike on a plot plan: read the label. A rectangle with an AT bubble inside is an analyser-shelter; a small square with JB is a junction-box.* | B, LER | Modular building / E-house datasheet (IEC 62271-202; A60 fire rating): Length → `length`; Width → `width`; Height → `height`; Cable cellar depth → `cellar`; Cladding → `cladding`; Main voltage → `kv`; Tag number → `tag` |
| `local-control-station` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/local-control-station.svg) | Field bubble marked HS (hand switch) beside the motor it starts and stops, joined to it by a dashed electrical signal line; the bubble is often annotated START / STOP or L-O-R. *HS bubbles with a horizontal bar are on the console, not in the field. Some P&IDs omit local stations entirely; they then appear only on the electrical layout as a small rectangle at the motor.* | LCS, HS, HMS | Local control station datasheet (IEC 60079-7, IEC 60947-5-1): Enclosure → `enclosure`; Ammeter → `ammeter`; Selector (L-O-R) → `selector`; Emergency stop → `estop`; Ammeter range → `amps`; Tag number → `tag` |
| `junction-box` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/junction-box.svg) | Small square or rectangle labelled JB plus its number, with field cables entering from the bottom and a multicore leaving towards the control room. *Appears on instrument location plans, cable block diagrams and electrical layouts, not on P&IDs. An LCS is a similar small box at a motor with push-buttons.* | JB, JBE, JBI | Junction box datasheet (IEC 60079-7 / IEC 60529): Size → `size`; Enclosure material → `enclosure`; Number of cable glands → `glands`; Tag number → `tag` |
| `lighting-mast` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/lighting-mast.svg) | On lighting layouts: the lamp symbol (circle with ×) for each floodlight, drawn on a mast or pole with its mounting height noted; floodlights sometimes add an arrow or wedge for the aiming direction. *Circle with × is the generic IEC lamp; a status beacon on F&G layouts uses a similar lamp with rays (alarm-beacon). Lighting is not shown on P&IDs.* |  | Lighting mast / floodlight datasheet (EN 40-3, IEC 60598-2-5): Mast style → `style`; Mounting height → `height`; Number of floodlights → `count`; Aiming tilt → `tilt`; Head access → `access`; Tag number → `tag` |
| `analyser-shelter` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/analyser-shelter.svg) | Building rectangle with doors at each end on the layout. On the P&ID the analysers inside (AT / AE bubbles) are often drawn within a dashed boundary marked "analyser house" with sample and return lines to the process. *Look for sample lines (small-bore, often with a sample cooler) running to a boundary that contains several AT bubbles. A building with no analysers is an E-house or LER.* | B, AT, AE, AIT | Analyser house datasheet (IEC 61285 / EEMUA 138): Length → `length`; Width → `width`; Height → `height`; Analyser panels → `panels`; Calibration gas bottles → `bottles`; Tag number → `tag` |
| `ups-battery-cabinet` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/ups-battery-cabinet.svg) | Rectifier (square with a diagonal, ~ above and = below) feeding a DC link with a battery (pairs of long and short parallel lines), then an inverter (= / ~), often with a static bypass switch drawn around them, inside a UPS boundary. *Square with a diagonal is the IEC converter: ~ / = is a rectifier or charger, = / ~ an inverter, ~ / ~ a frequency converter (VFD). Battery alone (long and short lines) is a DC battery bank.* | UPS, BAT, DB | UPS datasheet (IEC 62040-3, batteries IEC 60896-21): Rated output → `kva`; Battery cabinets → `batteryCabinets`; Tag number → `tag` |
| `vfd-cabinet` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/vfd-cabinet.svg) | IEC converter square with a diagonal and ~ on both sides (frequency converter), in the feeder to a motor (circle with M). On P&IDs the motor may carry an SC or VSD note, and the speed signal is an SC / SIC loop. *~ / ~ = frequency converter (VFD); ~ / = = rectifier; = / ~ = inverter. Soft starters are drawn as a box with a different note.* | VFD, VSD, U, SC, SIC, SY | Variable speed drive datasheet (IEC 61800-4 / IEC 61800-5-1): Rated motor power → `kw`; Rated voltage → `kv`; Tag number → `tag` |
| `neutral-earthing-resistor` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/neutral-earthing-resistor.svg) | Rectangle (IEC resistor) in the line from the transformer or generator star point down to the earth symbol (three shortening horizontal lines), often with a CT on the neutral. *IEC draws resistors as rectangles; ANSI drawings use a zig-zag. A rectangle in a neutral-to-earth connection is an NER; an earthing transformer is a zig-zag winding symbol instead.* | NER | Neutral earthing resistor datasheet (IEEE 32): System voltage → `kv`; Rated current → `amps`; Rated time → `seconds`; Neutral entry → `entry`; Tag number → `tag` |
| `navigation-aid` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/navigation-aid.svg) | On layouts: a lantern (circle) with light rays at the platform corners, labelled with its character (e.g. Mo(U) 15s, 10 nm) and a fog signal marked FOG or a horn outline. *Not on P&IDs. Obstruction lights on stacks and cranes are smaller red lamps; status beacons on F&G layouts are alarm-beacon.* |  | Aids to navigation specification (IALA R0139): Type → `kind`; Light colour → `color`; Nominal range → `range`; Mounting height → `height`; Tag number → `tag` |
| `ocean` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/ocean.svg) | Elevation: the mean sea level (MSL) or LAT line marked with an inverted triangle and its elevation (EL +0.000), with wave lines below it; jacket and riser drawings dimension the air gap and water depth from it. *Not on P&IDs. Metocean data (significant wave height, wind speed) comes from the project design basis.* |  | Metocean design basis: Significant wave height (Hs) → `waveHeight`; Wind speed (10 m) → `wind` |
| `sky` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/sky.svg) | Not drawn on P&IDs or layouts. Plot plans only carry a north arrow; sun path or lighting studies are separate reports. *Scene lighting for the 3D model, not plant equipment.* |  |  |
| `pressure-transmitter` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/pressure-transmitter.svg) | Plain circle (field-mounted bubble) with PT, PIT or PT plus loop number, joined by a short solid process connection line to the pipe or vessel. *A bubble with a horizontal bar across it is a DCS / control-room function (PIC, PI on the console), not a field device. PG / PI with no bar is a local gauge (pressure-gauge). PDT has two process connections (dp-transmitter). PST / PSH / PSL are switches (pressure-switch).* | PT, PIT, PE | Pressure transmitter specification form (ISA-TR20.00.01): Process connection rating → `rating`; Housing material / finish → `housing`; Sunshade → `sunshade`; Tag number → `tag` |
| `dp-transmitter` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/dp-transmitter.svg) | Field bubble with PDT (or PDIT, FT, LT) joined by two process connection lines, the high side and the low side, to two points on the pipe or vessel, e.g. either side of a filter, strainer or exchanger. *Two impulse lines from one bubble = differential pressure. If the two taps straddle an orifice plate the loop is a flow measurement (orifice-flowmeter); if they are on the top and bottom of a vessel it is a DP level transmitter. ISA codes here: FT = with orifice; LT = DP level.* | PDT, PDIT, FT, LT | Differential pressure transmitter specification form (ISA-TR20.00.01): Process connection rating → `rating`; Housing material / finish → `housing`; Sunshade → `sunshade`; Tag number → `tag` |
| `orifice-flowmeter` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/orifice-flowmeter.svg) | Two short parallel bars across the line (the orifice flanges with the plate between them), tagged FE, with two taps to an FT or FIT bubble. Some legends draw a single bar, or a box around the line with a diagonal. *With no transmitter and tag RO or FO it is a restriction orifice, not a meter. Venturi and flow nozzle are drawn as a converging / diverging outline instead. A flanged meter run with 10D / 5D straight lengths and a flow conditioner is still this element. ISA codes here: FO = restriction orifice.* | FE, FE, FT, FIT, FO | Orifice plate / flow element specification form (ISA-TR20.00.01; ISO 5167-2 calculation): Line size → `nps`; Flange rating → `rating`; Beta ratio (d/D) → `beta`; Upstream straight length → `upstream`; Downstream straight length → `downstream`; Tag number → `tag` |
| `coriolis-flowmeter` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/coriolis-flowmeter.svg) | Inline box on the line, often with a U or double-U loop drawn inside, joined to an FT / FIT bubble (integral transmitter). Frequently just a generic FE box with "CORIOLIS" or "MASS" written beside it. *ISA 5.1 has no dedicated Coriolis element, so legends differ; read the text beside the box, the instrument index or the datasheet for the technology. Common on chemical injection, condensate, fiscal liquid and test separator outlets. ISA codes here: FQT = totaliser.* | FE, FE, FT, FIT, FQT | Coriolis mass flowmeter specification form (ISA-TR20.00.01): Line size → `nps`; Flange rating → `rating`; Installation orientation (tubes) → `tubes`; Housing material / finish → `housing`; Tag number → `tag` |
| `ultrasonic-flowmeter` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/ultrasonic-flowmeter.svg) | Inline spool box with transducer marks on opposite sides and a diagonal acoustic path between them, joined to an FT bubble. Many legends just write "USM" or "UFM" beside a generic FE box. *Fiscal gas metering runs (AGA 9) are usually multipath ultrasonic; a clamp-on meter is drawn on the outside of the pipe with no break in the line. Check the technology in the instrument index.* | FE, FE, FT, FIT, FQ | Ultrasonic flowmeter specification form (ISA-TR20.00.01; AGA 9 / ISO 17089-1): Line size → `nps`; Flange rating → `rating`; Number of acoustic paths → `paths`; Transducer shroud → `shroud`; Housing material / finish → `housing`; Tag number → `tag` |
| `guided-wave-radar` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/guided-wave-radar.svg) | LT / LIT field bubble on top of an external chamber (cage) bolted to the vessel by an upper and a lower connection, with a probe line hanging down inside the chamber; or the bubble sits directly on a vessel top nozzle. *A bridle (vertical standpipe) carrying several instruments is common: the LT, an LG (magnetic-level-gauge) and LSHH / LSLL switches all hang off it. Non-contact radar uses the same LT bubble without a probe. Interface level is LT with the service written beside it.* | LT, LIT, LE | Level transmitter specification form (ISA-TR20.00.01): External chamber → `chamber`; Probe length → `length`; Process connection size → `nps`; Chamber size → `chamberNps`; Flange rating → `rating`; Housing material / finish → `housing`; Tag number → `tag` |
| `magnetic-level-gauge` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/magnetic-level-gauge.svg) | Tall narrow chamber beside the vessel with an upper and a lower side connection (isolation valves on each, vent on top, drain below), labelled with an LG or LI bubble. *Same chamber with a transmitter strapped on is LG plus LT on one bridle (set transmitter). A plain glass (reflex / transparent) gauge is drawn the same and is also tagged LG; check the datasheet.* | LG, LG, LI | Level gauge specification form (ISA-TR20.00.01): Centre-to-centre → `length`; Process connection size → `nps`; Chamber size → `chamberNps`; Flange rating → `rating`; Clamp-on transmitter → `transmitter`; Level switches → `switches`; Tag number → `tag` |
| `temperature-transmitter` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/temperature-transmitter.svg) | TT or TIT field bubble joined to a thermowell (a short U-shaped pocket pushed into the pipe, sometimes tagged TW), on the pipe or vessel. *TE (element) plus TT (transmitter) of the same loop are one physical item. TI / TG with no transmitter is a dial thermometer (temperature-gauge). A TW bubble on its own is a spare or test thermowell.* | TT, TIT, TE, TW | Temperature transmitter + thermowell specification forms (ISA-TR20.00.01; ASME PTC 19.3 TW): Thermowell flange size → `nps`; Flange rating → `rating`; Insertion length (U) → `insertion`; Lagging extension (T) → `extension`; Housing material / finish → `housing`; Tag number → `tag` |
| `pressure-gauge` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/pressure-gauge.svg) | Field bubble marked PI (or PG on some legends) joined to the pipe by a short process line; no signal line leaves it, because it is a local dial. *Same bubble as a transmitter but with PI / PG and no signal line. A bubble with a bar through it reading PI is a console indication, not a gauge. PDI / PDG across a filter is a differential gauge.* | PG, PI, PG | Pressure gauge specification form (ISA-TR20.00.01; EN 837-1 / ASME B40.100): Flange rating → `rating`; Dial size → `dial`; Range (max) → `max`; Siphon → `siphon`; Tag number → `tag` |
| `temperature-gauge` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/temperature-gauge.svg) | Field bubble marked TI (or TG) on a thermowell pocket in the pipe; no signal line. *Same as the temperature transmitter but with TI / TG. A test thermowell with no instrument is a TW bubble alone.* | TG, TI, TG, TW | Bimetal thermometer + thermowell specification forms (ISA-TR20.00.01; ASME B40.200): Thermowell flange size → `nps`; Flange rating → `rating`; Insertion length (U) → `insertion`; Lagging extension (T) → `extension`; Dial size → `dial`; Range (max) → `max`; Tag number → `tag` |
| `magnetic-flowmeter` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/magnetic-flowmeter.svg) | Inline box (or circle) on the line marked M, joined to an FT bubble. Some legends use a generic FE with "MAG" written beside it. *Only for conductive liquids (water, produced water, seawater, chemicals); a meter on a gas line is never a mag meter. A circle with M on a valve stem is a motor actuator, not a flowmeter.* | FE, FE, FT, FIT | Magnetic flowmeter specification form (ISA-TR20.00.01): Line size → `nps`; Flange rating → `rating`; Liner material → `liner`; Housing material / finish → `housing`; Tag number → `tag` |
| `vortex-flowmeter` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/vortex-flowmeter.svg) | Inline box with a small bluff-body triangle (the shedder bar) and wavy vortex lines downstream, joined to an FT bubble. Often a generic FE with "VORTEX" written beside it. *Used on steam, fuel gas, utility gas and clean liquids. Read the instrument index to confirm the technology when the legend only gives a generic flow element.* | FE, FE, FT, FIT | Vortex flowmeter specification form (ISA-TR20.00.01): Line size → `nps`; Flange rating → `rating`; Extended (high-temperature) neck → `neck`; Housing material / finish → `housing`; Tag number → `tag` |
| `level-switch` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/level-switch.svg) | Field bubble with LS plus H / HH / L / LL (LSH, LSHH, LSLL) on a side connection of a vessel or bridle at the trip height. In a SIS it is often drawn with a diamond or hexagon tag for the logic it feeds. *S = switch, so the bubble has no transmitter letter T. Trip levels are written beside it in mm or %. Vibrating fork, float and displacer switches all use the same bubble.* | LSH, LSHH, LSL, LSLL, LS | Level switch specification form (ISA-TR20.00.01): Process connection size → `nps`; Flange rating → `rating`; Insertion length → `length`; Housing material / finish → `housing`; Tag number → `tag` |
| `pressure-switch` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/pressure-switch.svg) | Field bubble with PS plus H / HH / L / LL (PSH, PSHH, PSL, PSLL) on a short process connection, usually feeding a trip. *Switches have S as the function letter and no T. A PSV is a relief valve, not a switch: PSV has V for valve. PDSH across a filter is a differential pressure switch.* | PSH, PSHH, PSL, PSLL, PS | Pressure switch specification form (ISA-TR20.00.01): Flange rating → `rating`; Housing material / finish → `housing`; Tag number → `tag` |
| `vibration-probe` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/vibration-probe.svg) | A VE or VT bubble joined to a small square or dot on a motor, pump, compressor or bearing outline, often in A / B or X / Y pairs, feeding VI / VA / VSHH functions in the DCS, SIS or CMS. *V as the first letter is vibration (ISA 5.1). One vibration-probe per monitored bearing; pair for X-Y proximity probes, kind accelerometer for casing sensors. ZE on a machine is an axial position probe and maps here too. Voting such as 1oo2 between A and B means two sensors exist.* | VE, VT, VE, VT, VXE, VYE, VI, VSHH | Machinery protection system datasheet (API 670): Transducer type → `kind`; X-Y pair → `pair`; Shaft centreline height → `shaftHeight`; Tag number → `tag` |
| `control-console` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/control-console.svg) | Plan view: a run of desk segments (straight, angled or curved) with the monitor line along the back edge and operator chairs as circles in front, laid out facing the video wall. *Only on control room layouts. A straight table with a chair is a desk; a grid of tiles on a wall is the video wall.* | OWS | Control room layout / console specification (ISO 11064-3 / -4): Segments → `segments`; Layout → `layout`; Segment angle → `angle`; Segment width → `segmentWidth`; Depth → `depth`; Sit-stand → `sitStand`; Desk height → `deskHeight`; Monitors per segment → `monitorsPerSegment`; Monitor rows → `rows`; Monitor size → `monitorSize`; Tag number → `tag` |
| `video-wall` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/video-wall.svg) | Elevation: a grid of display tiles (rows × columns) on a frame with a base cabinet; in plan, a long thin rectangle along the CCR wall with the viewing distance to the consoles dimensioned. *Only on control room drawings.* |  | Large-screen display specification (ISO 11064-4): Rows → `rows`; Columns → `cols`; Tile diagonal → `diagonal`; Bezel width → `bezel`; Technology → `technology`; Mounting → `mount`; Bottom edge height → `elevation`; Video wall controller → `controller`; Tag number → `tag` |
| `door` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/door.svg) | Plan view: a gap in the wall with the door leaf drawn as a line at 90° and a quarter-circle arc for the swing; double doors have two leaves and arcs, sliding doors a leaf parallel to the wall. The fire rating (A60, H120) is noted on the door schedule. *Arc = hinged door; the hinge side is the arc centre. Blast doors are drawn thicker; roller shutters as a dashed line across the opening.* |  | Door schedule (IMO FTP Code A60 / H120, EN 1125 / EN 1154 hardware): Type → `kind`; Fire rating → `fireRating`; Clear width → `width`; Clear height → `height`; Handing → `hand`; Hardware → `hardware`; Vision panel → `visionPanel`; Tag number → `tag` |
| `window` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/window.svg) | Plan view: the wall is interrupted and parallel thin lines across the opening show the glazing; sill height and fire / blast rating are on the window schedule. *A gap with an arc is a door; a gap with thin parallel lines is a window.* |  | Window schedule (IMO FTP Code A60 / H120, ISO 3903): Type → `kind`; Fire rating → `fireRating`; Width → `width`; Height → `height`; Sill height → `sill`; Panes → `panes`; Sunshade → `sunshade`; Tag number → `tag` |
| `room` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/room.svg) | Plan view: double-line walls enclosing the room with door and window openings and the room name and number written inside; raised floors noted RAF with the floor height. *Rooms are background for consoles, cabinets and furniture. A single building rectangle on a plot plan is an e-house or module.* |  | Room data sheet (ISO 11064-3; EN 12825 raised floor): Width → `width`; Depth → `depth`; Ceiling height → `height`; Wall thickness → `wallThickness`; Raised floor → `raisedFloor`; Raised floor height → `floorHeight`; Ceiling → `ceiling`; Cable tray → `cableTray`; Fire rating → `fireRating`; Room name → `label`; Tag number → `tag` |
| `system-cabinet` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/system-cabinet.svg) | Plan view: a row of squares (cabinets) against a wall or back to back, with door swing arcs on the front and the system (DCS, SIS, F&G, marshalling) written on each; front and rear access clearances dashed. *Only on equipment-room layouts. Switchgear line-ups look similar but are deeper and labelled with feeders.* |  | Cabinet layout / system cabinet specification (IEC 61439, IEC 60297): Number of cabinets → `count`; System → `system`; Width → `width`; Depth → `depth`; Height → `height`; Front door → `door`; Rear doors → `rearDoors`; Cable entry → `cableEntry`; Tag number → `tag` |
| `operator-chair` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/operator-chair.svg) | Plan view: a rounded seat square with a curved backrest and armrests, placed at a console or desk; often just a circle. *Furniture appears only on control room and office layouts.* |  | Furniture schedule (EN 1335, BS 5459-2 24-hour use): Seat height → `seatHeight`; Headrest → `headrest`; Armrests → `arms` |
| `desk` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/desk.svg) | Plan view: a rectangle (desk or table) with monitors drawn as thick lines along the back edge and chairs as circles or seat shapes around it. *A curved or angled run of desks with many monitors is a control-console.* |  | Furniture schedule (EN 527-1): Layout → `layout`; Width → `width`; Depth → `depth`; Monitors → `monitors`; Seats → `seats`; Tag number → `tag` |
| `wall-display` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/wall-display.svg) | Control room or equipment-room layout: a thin rectangle on the wall (plan) or a framed screen on a bracket (elevation), labelled with its size and content. *A single screen; a grid of tiles is the video wall.* |  | Display specification (ISO 11064-4): Screen size → `size`; Mounting → `mount`; Style → `style`; Mounting height → `elevation`; Tag number → `tag` |
| `cctv-camera` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/cctv-camera.svg) | Telecom layout: a camera symbol (small box with a lens) with its field-of-view wedge drawn dashed in the direction it looks; PTZ cameras marked PTZ with a full circle of coverage. *A wedge from a camera box is the CCTV view; a wedge from a circle with F is a flame detector cone. Not on P&IDs.* | CCTV | CCTV camera datasheet (IEC 60079-1, IEC 60529): Type → `kind`; Mounting → `mount`; Mounting height → `height`; Wiper → `wiper`; Junction box → `junctionBox`; Tag number → `tag` |
| `fire-alarm-panel` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/fire-alarm-panel.svg) | On F&G block diagrams and room layouts: a rectangle labelled FACP, F&G or ESD with the zones it serves; detectors and call points are wired to it in loops. *An F&G or ESD mimic panel in the CCR; the logic itself lives in the system cabinets (system-cabinet).* | FACP, FGP | Fire alarm control panel datasheet (EN 54-2 / IEC 61511): Panel type → `panel`; Mounting → `mount`; Zones → `zones`; Mounting height → `elevation`; Tag number → `tag` |
| `pedestal-crane` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/pedestal-crane.svg) | Plan view: the pedestal as a circle at the crane position with the maximum (and minimum) working radius drawn as large dashed circles around it, the boom as a line, and laydown areas and lift paths inside the radius; tagged CR- with SWL at radius. *The large dashed reach circle is the clue. A small post with a short jib and no reach study is a davit-crane. Not on P&IDs, except a diesel or hydraulic utility tie-in.* | CR | Offshore crane datasheet (API Spec 2C / EN 13852-1): Boom length → `boomLength`; Pedestal height → `pedestalHeight`; Safe working load → `swl`; Boom rest → `boomRest`; Tag number → `tag` |
| `shipping-container` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/shipping-container.svg) | Plan view: a rectangle at the ISO footprint (10, 20 or 40 ft) in a laydown area, often with a diagonal cross meaning "laydown / temporary", the door end marked by a thicker line, and its size written inside. *Laydown areas are rectangles with a cross or hatch; a container is one sized like an ISO box. Baskets are open and smaller; tote tanks are near-square.* |  | Offshore container certificate / specification (DNV 2.7-1, ISO 668): Size → `size`; Marking → `marking`; Lifting set → `liftingSet`; Tag number → `tag` |
| `cargo-basket` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/cargo-basket.svg) | Elevation: an open-topped frame with mesh sides hanging from a four-leg sling set to a master link; in plan, a long rectangle in the laydown area. *Open top and mesh sides tell it from a closed container. Not on P&IDs.* |  | Offshore container certificate (DNV 2.7-1 / EN 12079-1): Length → `length`; Width → `width`; Height → `height`; Safe working load → `swl`; Lifting set → `liftingSet`; Tag number → `tag` |
| `monorail-hoist` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/monorail-hoist.svg) | Plan view: a dash-dot or thick line along the runway beam labelled "monorail, SWL x t" from the equipment it serves to the drop or laydown zone; in elevation a beam with a trolley, hoist block and hook. *Shown on mechanical handling and layout drawings over pumps, compressors and exchangers that need lifting. Not on P&IDs.* |  | Hoist and runway datasheet (EN 14492-2 / FEM 9.511): Runway length → `length`; Beam height → `height`; Safe working load → `swl`; Tag number → `tag` |
| `lifeboat-davit` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/lifeboat-davit.svg) | On escape and lifesaving plans: a boat outline (pointed or rounded ends) at the muster station, under davit arms, with its capacity (e.g. 50 P) written inside; often marked TEMPSC. *Liferafts are drawn as small circles or canisters. Never on P&IDs.* | TEMPSC | Lifeboat and davit certificate / schedule (SOLAS LSA Code IV/4.6, VI/6.1): Certified capacity (persons) → `capacity`; Tag number → `tag` |
| `tote-tank` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/tote-tank.svg) | Layout: a near-square frame with the tank outline inside, in the chemical laydown; on P&IDs a small vessel or "tote" box with a hose connection to the chemical injection skid suction. *A permanent chemical tank is part of the chemical-injection-skid. Totes are temporary, hose-connected supplies.* | IBC | Portable tank certificate (DNV 2.7-1 / EN 12079-1): Capacity → `volume`; Lifting set → `liftingSet`; Tag number → `tag` |
| `davit-crane` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/davit-crane.svg) | Elevation: a post curving into a short jib with a hook; in plan, a small circle with a short reach radius (dashed) over the item it serves, labelled with SWL. *Small reach circle (a few metres) versus the large reach of a pedestal crane. Not on P&IDs.* | DAV, CR | Davit datasheet (EN 13852-1 / EN 13157): Outreach → `reach`; Height under hook → `height`; Safe working load → `swl`; Tag number → `tag` |
| `gas-cylinder-quad` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/gas-cylinder-quad.svg) | Layout: a square frame filled with small circles (the cylinders). On P&IDs a bottle rack is drawn as one or more small capsules joined to a manifold with a regulator (PCV) on the outlet. *Nitrogen back-up racks and calibration gas bottles use the same drawing; read the gas. A nitrogen generator package is a separate item.* |  | Cylinder bundle certificate (EN 12079-1 / ISO 10961): Number of cylinders → `count`; Gas → `gas`; Lifting set → `liftingSet`; Tag number → `tag` |
| `marine-loading-arm` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/marine-loading-arm.svg) | An articulated line from the jetty riser through swivel joints (small circles) at the base, apex and outboard end, ending in the emergency release coupling (two close bars with valves) and the ship manifold flange; a counterweight box on the inboard arm. *Swivels plus the ERS mark tell it from a hose. Truck loading arms are smaller and drawn with the truck outline. ISA codes here: XV = ERS.* | MLA, XV, ZS | Marine loading arm datasheet (OCIMF / EN 1474): Nominal size → `nps`; Flange rating → `rating`; Outreach → `reach`; Emergency release system → `ers`; Hydraulic operation → `hydraulic`; Tag number → `tag` |
| `truck-loading-bay` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/truck-loading-bay.svg) | Per bay: block valve, strainer, meter (FE / FQ, often PD), digital set-stop control valve and the loading arm or hose dropping to a road tanker outline; on the plot plan, lanes under a canopy rectangle. *A meter run ending at a tanker outline is the clue. Marine loading uses articulated arms to a ship manifold instead.* | TLB, FQ, FQIC, FV, XV | Loading bay specification (API RP 1004 / EN 13083, API 2610): Number of bays → `bays`; Product → `product`; Loading method → `loading`; Line size → `nps`; Flange rating → `rating`; Tag number → `tag` |
| `pipeline-valve-station` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/pipeline-valve-station.svg) | A mainline ball valve below the grade line with its stem extended up to an above-grade actuator (rectangle: gas-over-oil or electric), and blowdown / bypass branches rising to their own valves; often within a fenced compound outline. *The grade line with a buried valve and stem extension identifies it. Topsides ESDVs are esd-valve.* | BVS, MLV, SDV, XV, SDV, PT, ZS | Pipeline valve datasheet (API 6D / ISO 14313) + actuator sheet: Nominal size → `nps`; Pressure class → `rating`; Actuator type → `actuator`; Depth of cover → `cover`; Tag number → `tag` |
| `packaged-boiler` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/packaged-boiler.svg) | A horizontal shell (capsule) with fire tubes drawn as parallel lines inside, a burner box with the fuel line on the front end, a flue stack on top, steam outlet from the top and feedwater inlet; often inside a package boundary with the feedwater pumps. *Shell with tubes plus burner and stack = fire-tube boiler. A fired heater is a vertical firebox with a process coil; a TEG reboiler is a smaller fire-tube capsule inside a regeneration package.* | BLR, H | Steam boiler datasheet (EN 12953 / ASME Section I): Steam output → `steam`; Design pressure → `pressure`; Flange rating → `rating`; Fuel → `fuel`; Access platform → `platform`; Tag number → `tag` |
| `oily-water-separator` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/oily-water-separator.svg) | An open rectangular basin (no top line) with inclined parallel plates drawn as slanted lines in the middle, an inlet chamber with a baffle, an oil skimmer or weir to the oil outlet, a sludge draw-off at the bottom and the clean water outlet over a weir at the far end. *Slanted plate pack in an open basin = CPI / plate interceptor. A closed horizontal vessel with weirs is a separator; produced water offshore uses hydrocyclones and degassers instead.* | V, T, X | Oil-water separator datasheet (API 421): Design flow → `flow`; Construction → `construction`; Inlet size → `inletNps`; Oil outlet size → `oilNps`; Flange rating → `rating`; Covers → `covers`; Tag number → `tag` |
| `bund-wall` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/bund-wall.svg) | Plot plan: a double-line rectangle (the wall thickness) enclosing the tank outline, with the bund drain sump in a corner and a normally closed drain valve outside the wall; the bund capacity and wall height are noted. *A double-line enclosure around tanks = bund. On P&IDs only the bund drain line and its locked-closed valve appear.* | BW | Secondary containment design (NFPA 30 / EI 19, EN 1992-3): Length → `length`; Width → `width`; Wall height → `height`; Wall thickness → `thickness`; Access stairs → `stairs`; Drain size → `drainNps`; Tag number → `tag` |
| `perimeter-fence` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/perimeter-fence.svg) | Site plan: a line with crosses at intervals (-x-x-) along the boundary, gates shown as a swing (leaf and arc) or a sliding leaf, with fence height and type noted. *Only on site plans. The crosses tell it from a wall (solid double line) or a kerb.* | FNC | Fencing specification (BS 1722-10 / -12, ASTM F567): Run length → `length`; Style → `style`; Height → `height`; Topping → `topping`; Gate → `gate`; Gate width → `gateWidth`; Finish → `finish`; Tag number → `tag` |
| `hv-circuit-breaker` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/hv-circuit-breaker.svg) | Single-line: a switch blade (a line at an angle) with a small × on the fixed contact, in the feeder between busbar and line or transformer; often drawn inside a bay with disconnectors on either side. *IEC symbols: × on the contact = circuit breaker; a bar across the contact = disconnector; a blade to the earth symbol = earthing switch. ANSI drawings use a square box with device number 52. QA / QB / QC are IEC 81346-2 class letters for breaker, disconnector and earthing switch.* | CB, QA | HV circuit breaker datasheet (IEC 62271-100): Rated voltage → `kv`; External insulation → `insulation`; Tag number → `tag` |
| `disconnector` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/disconnector.svg) | Single-line: a switch blade with a short bar across the fixed contact (disconnector), usually next to an earthing switch drawn as a second blade going to the earth symbol (three shortening lines). *Bar on the contact = disconnector (isolator, no load breaking); × = circuit breaker. Some drawings tag disconnectors DS. ANSI device numbers are 89 for the disconnector and 57 for the earthing switch.* | QB, QC | HV disconnector datasheet (IEC 62271-102): Rated voltage → `kv`; Style → `style`; External insulation → `insulation`; Tag number → `tag` |
| `instrument-transformer` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/instrument-transformer.svg) | Single-line: a current transformer is a small circle threaded on the primary conductor (or a loop) with its secondary leads; a voltage transformer is a pair of small overlapping circles connected from the line to earth. A CVT adds a capacitor stack (two parallel plates) above the VT. *Circle on the line = CT; two circles from line to earth = VT. Small overlapping circles in a feeder (not to earth) are a power transformer. CT also collides with cooling-tower tags on process drawings: context decides.* | CT, VT, CVT | Instrument transformer datasheet (IEC 61869-2 / -3 / -5): Type → `kind`; Rated voltage → `kv`; External insulation → `insulation`; Tag number → `tag` |
| `surge-arrester` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/surge-arrester.svg) | Single-line: a rectangle (non-linear resistor) with an arrow inside pointing to earth, connected from the line to the earth symbol, usually at transformer terminals and line entries. *Rectangle with an internal arrow to earth = surge arrester; a plain rectangle to earth on a neutral is a neutral earthing resistor. LA (lightning arrester) is an older name.* | SA, LA | Surge arrester datasheet (IEC 60099-4): System voltage → `kv`; Housing insulation → `insulation`; Tag number → `tag` |
| `busbar-gantry` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/busbar-gantry.svg) | Single-line: a thick horizontal line (busbar) with bay connections dropping from it at dots; on substation layouts and elevations the gantry is a pair of lattice columns with a girder carrying strain insulator strings and the bus conductors. *A thick line with feeders = busbar. Double-busbar stations show two parallel thick lines with a coupler bay between them.* | BB, BUS | Substation design basis (IEC 61936-1, IEC 60383 insulators): Number of bays → `bays`; Rated voltage → `kv`; Gantry span → `span`; Tag number → `tag` |
| `industrial-building` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/industrial-building.svg) | Site or floor plan: a rectangle on the structural grid (dash-dot), with roller-shutter doors shown as dashed lines across openings and personnel doors as swing arcs; the building name and use are written inside. *Buildings are identified by label on plot plans; an E-house or analyser shelter is smaller and skid-based. Not on P&IDs.* | B, BLDG | Building specification (EN 1993-1-1 frame, EN 14509 cladding, EN 13241 doors): Use → `kind`; Length → `length`; Width → `width`; Eaves height → `eaves`; Roof pitch → `pitch`; Roller doors → `rollerDoors`; Personnel doors → `personnelDoors`; Tag number → `tag` |
| `gatehouse` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/gatehouse.svg) | Site plan: a small hut rectangle on a kerbed island beside the lane, a boom barrier drawn as a thick line from a pivot across the lane, and lane direction arrows. *Only on site and security plans.* | GH | Barrier / gate specification (EN 12453, EN 13241): Lane width → `laneWidth`; Tag number → `tag` |
| `chemical-injection-skid` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/chemical-injection-skid.svg) | Dash-dot package boundary containing a small storage tank, a suction header and one or more metering pumps (small circles with a diagonal arrow), with injection lines (CI / MI, ½"–1") leaving to the injection points, each with a check valve and isolation at the quill. *The chemical (demulsifier, corrosion inhibitor, scale inhibitor, methanol, biocide) is written on the tank or on the outgoing lines. Vendor packages are often a single box with only the battery-limit connections shown.* | C, X, A | Chemical injection package datasheet (API 675 pumps): Number of pumps → `pumps`; Tank diameter → `tankDiameter`; Tank height → `tankHeight`; Pump driver power → `kw`; Fill connection size → `fillNps`; Injection outlet size → `outletNps`; Outlet flange rating → `outletRating`; Chemical → `chemical`; Canopy → `canopy`; Tag number → `tag` |
| `metering-skid` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/metering-skid.svg) | Dash-dot boundary with an inlet header and outlet header joined by parallel meter runs; each run has an inlet block valve, strainer, flow element (FE / FQ, ultrasonic or turbine) with PT and TT, and an outlet valve; a prover connection and sampler may be shown. *Parallel identical runs between two headers are the signature. A single flowmeter in a line is an instrument, not a metering skid; a compact prover (X-R155 type) is a separate box connected by the prover loop. ISA codes here: AT = sampler / densitometer.* | X, A, FE, FT, FQI, FQ, PT, TT, AT | Fiscal metering system datasheet (API MPMS Ch. 4 / 5, AGA 9 / ISO 17089-1): Number of meter runs → `runs`; Meter type → `meterType`; Header size → `headerNps`; Meter run size → `runNps`; Flange rating → `rating`; Tag number → `tag` |
| `instrument-air-package` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/instrument-air-package.svg) | Dash-dot package boundary containing an air compressor (screw symbol or generic compressor), a twin-tower desiccant dryer (two tall capsules side by side), filters, and the air receiver (vertical vessel) before the instrument-air (IA) header. *Two identical tall capsules side by side = dryer towers. Often only the package box with IA outlet and the receiver are shown on the utilities P&ID. ISA codes here: AT = dew point.* | X, A, PT, PSLL, AT | Instrument air package datasheet (ISO 8573-1 class, ISO 1217 capacity): Compressor motor power → `kw`; Receiver diameter → `receiverDiameter`; Receiver height → `receiverHeight`; Design pressure → `pressure`; Outlet size → `outletNps`; Tag number → `tag` |
| `teg-regeneration` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/teg-regeneration.svg) | Dash-dot package boundary with a horizontal reboiler (capsule with a U-shaped fire tube drawn inside), a short packed still column standing on top of it with the vent to atmosphere, a surge drum and lean-glycol pumps; rich TEG in, lean TEG out to the contactor. *The reboiler with a fire-tube and a vertical still on top is the clue. The tall TEG contactor column itself is a separate item (column).* | X, A, C | Glycol regeneration package datasheet (API 12GDU): Reboiler diameter → `reboilerDiameter`; Reboiler length → `reboilerLength`; Still column diameter → `stillDiameter`; Exhaust stack height → `stackHeight`; Number of lean glycol pumps → `pumps`; Pump driver power → `kw`; Glycol connection size → `glycolNps`; Lean glycol rating → `leanRating`; Tag number → `tag` |
| `hydraulic-power-unit` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/hydraulic-power-unit.svg) | Dash-dot package boundary with an open reservoir (U-shaped tank), hydraulic pumps (circle with a filled triangle pointing outward on the outlet), filters, accumulators (vertical capsules with a dividing line) and the HP / LP supply headers leaving as hydraulic lines. *ISO 1219 symbols (filled triangle in a circle = hydraulic pump; capsule with a line = accumulator) identify a hydraulic system. The WHCP sits downstream with one line per actuator.* | X, HPU, A, PT, LSL, PSL | Hydraulic power unit datasheet (ISO 4413 / API 6A control systems): Reservoir volume → `reservoir`; Number of pumps → `pumps`; Pump motor power → `kw`; Accumulators → `accumulators`; Supply connection size → `supplyNps`; Supply rating → `supplyRating`; Return connection size → `returnNps`; Tag number → `tag` |
| `nitrogen-generator` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/nitrogen-generator.svg) | Dash-dot package boundary with air filters (diamond with a dashed line), an air heater, membrane modules (rectangles with a diagonal dashed membrane line, permeate vented to atmosphere) and a nitrogen receiver before the N2 outlet. *Membrane modules with a vent line identify the generator; a nitrogen bottle rack is a gas-cylinder-quad. Often shown on the utilities P&ID as a single package box. ISA codes here: AT = O2.* | X, A, AT, PT, FT | Nitrogen generator package datasheet (ISO 8573-1 feed air; ASME VIII-1 receiver): Membrane modules → `modules`; Receiver diameter → `receiverDiameter`; Receiver height → `receiverHeight`; Design pressure → `pressure`; Air inlet size → `airNps`; N2 outlet size → `n2Nps`; Tag number → `tag` |
| `hydrocyclone-package` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/hydrocyclone-package.svg) | Horizontal vessel(s) with cyclone liners drawn as long cones (or a single inverted cone, the generic cyclone symbol), produced water in at the inlet header, clean water out, and the oily reject to the reject header controlled by a PDV / PDIC ratio loop. *Cones inside a vessel = hydrocyclones (or a desander if on the well stream with a sand accumulator). Reject-ratio control is the PDIC loop between inlet, outlet and reject.* | X, A, HC, PDV, PDIC, PDT | Hydrocyclone package datasheet (ASME VIII-1): Number of vessels → `vessels`; Vessel diameter → `vesselDiameter`; Vessel length → `vesselLength`; Design pressure → `pressure`; Inlet size → `inletNps`; Outlet size → `outletNps`; Reject size → `rejectNps`; Flange rating → `rating`; Tag number → `tag` |
| `compact-prover` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/compact-prover.svg) | A horizontal flow tube with a piston (displacer) drawn inside and two detector switches on top marking the calibrated volume, connected by a prover loop with valves to the metering skid; often just a box labelled "prover". *Piston in a tube with detector marks = compact prover; a long U-shaped pipe loop with spheres is a conventional ball prover. ISA codes here: ZS = detector.* | X, A, ZS, PT, TT | Meter prover datasheet (API MPMS Ch. 4.2): Connection size → `nps`; Flange rating → `rating`; Flow tube length → `tubeLength`; Tag number → `tag` |
| `water-filter-package` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/water-filter-package.svg) | Dash-dot package boundary with two to four vertical filter vessels in parallel between inlet and outlet headers, each crossed by dashed lines for the media bed, plus backwash and air-scour headers with butterfly valves. *Parallel identical filter vessels with backwash lines = multimedia filter package. A single cartridge housing is cartridge-filter.* | X, A, F, PDT, PDI, FT | Filter package datasheet (AWWA B100 / ASME VIII-1): Number of filters → `filters`; Filter diameter → `filterDiameter`; Filter height → `filterHeight`; Design pressure → `pressure`; Header size → `headerNps`; Branch size → `branchNps`; Flange rating → `rating`; Tag number → `tag` |
| `hypochlorite-generator` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/hypochlorite-generator.svg) | Dash-dot package boundary with a seawater strainer, electrolyser cells (boxes with parallel electrode plates) fed from a DC rectifier (square with diagonal, ~ / =), a degassing tank venting hydrogen, and hypochlorite dosing out to the seawater caissons. *Electrolyser cells plus a rectifier identify it; a chemical-injection-skid has a tank and metering pumps instead. ISA codes here: AT = H2.* | X, A, CL, FT, FSL, AT | Electrochlorination package datasheet (IEC 60146 rectifier): Electrolyser cells → `cells`; Degassing tank diameter → `tankDiameter`; Degassing tank height → `tankHeight`; Seawater inlet size → `seawaterNps`; Hypochlorite outlet size → `hypoNps`; Tag number → `tag` |
| `weld-neck-flange` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/weld-neck-flange.svg) | In section: a flange disc with a long tapered hub narrowing to the pipe wall and a butt weld at the hub end. On P&IDs just a short bar across the line; on isometrics a bar with a weld dot. *The flange type comes from the piping class, not the P&ID. The long taper identifies weld-neck; slip-on and socket-weld have short hubs; lap-joint has a loose ring on a stub end.* | WN | Piping class / flange bill of materials (ASME B16.5 / B16.47): Nominal size → `nps`; Pressure class → `rating`; Facing → `facing`; Bore (schedule) → `schedule`; Tag number → `tag` |
| `slip-on-flange` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/slip-on-flange.svg) | In section: a flange with a short hub slid over the pipe, the pipe end set back from the face, with fillet welds inside the bore and at the hub. On P&IDs a short bar across the line. *Pipe passing into the flange bore with two fillet welds = slip-on. Weld-neck has a long tapered hub and one butt weld.* | SO | Piping class / flange bill of materials (ASME B16.5): Nominal size → `nps`; Pressure class → `rating`; Facing → `facing`; Pipe schedule → `schedule`; Tag number → `tag` |
| `socket-weld-flange` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/socket-weld-flange.svg) | In section: a small-bore flange with a socket the pipe slides into against a shoulder (small gap at the bottom), and one fillet weld at the hub. On P&IDs a short bar on a small-bore (≤ 2") line. *Socket-weld is small-bore only (NPS ½–3). Threaded flanges show thread hatching in the bore instead of a weld.* | SW | Piping class / flange bill of materials (ASME B16.5, B16.11): Nominal size → `nps`; Pressure class → `rating`; Facing → `facing`; Pipe schedule → `schedule`; Tag number → `tag` |
| `threaded-flange` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/threaded-flange.svg) | In section: a flange with a short hub and thread marks (zig-zag) in the bore where the pipe screws in, sometimes with a seal weld. On P&IDs a short bar, usually on utility or small-bore lines. *Zig-zag thread lines in the bore identify it. Most offshore hydrocarbon piping classes do not allow threaded joints; expect it on utility water or air.* | THD, SCRD | Piping class / flange bill of materials (ASME B16.5, B1.20.1): Nominal size → `nps`; Pressure class → `rating`; Facing → `facing`; Pipe schedule → `schedule`; Seal weld → `sealWeld`; Tag number → `tag` |
| `lap-joint-flange` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/lap-joint-flange.svg) | In section: a stub end (pipe with a flared lap at the face) with a loose backing flange sitting behind the lap, not welded to the pipe. On P&IDs a short bar like any flange. *The loose ring behind a lap identifies it. Used on stainless or alloy lines where the backing flange can be carbon steel, and where bolt holes must be lined up after welding.* | LJ | Piping class / flange bill of materials (ASME B16.5, MSS SP-43): Nominal size → `nps`; Pressure class → `rating`; Stub-end schedule → `schedule`; Stub-end pattern → `pattern`; Backing flange material → `backing`; Tag number → `tag` |
| `swivel-ring-flange` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/swivel-ring-flange.svg) | In section: a weld hub carrying the gasket face with a separate loose ring that can rotate around it to align bolt holes; drawn with a curved arrow on some pipeline tie-in details. On P&IDs a flange bar, often at a riser or spool tie-in. *Found at subsea and riser tie-ins where bolt-hole alignment is hard. On P&IDs it is indistinguishable from other flanges; read the tie-in detail.* | SRF | Pipeline flange datasheet (ASME B16.5 drilling, MSS SP-44): Nominal size → `nps`; Pressure class → `rating`; Facing → `facing`; Pipe schedule → `schedule`; Tag number → `tag` |
| `olet` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/olet.svg) | On P&IDs a branch is just a line meeting another line with a dot (like a tee); on isometrics a branch outlet is a small saddle-shaped boss on the run pipe with the branch rising from it, noted WOL, SOL, TOL, NOL, EOL or LOL. *P&IDs do not distinguish an olet from a tee: the piping class branch table decides (small branches off large runs are olets). Instrument connections and vents and drains are usually olets.* | WOL, SOL, TOL, NOL, EOL, LOL | Piping class branch table / bill of materials (MSS SP-97): Olet type → `kind`; Run size → `runNps`; Branch size → `nps`; Run schedule → `runSchedule`; Branch schedule → `schedule`; Pressure class → `pressureClass`; Branch end → `end` |
| `small-bore-fitting` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/small-bore-fitting.svg) | Not drawn as a separate item on P&IDs: small-bore vents, drains and instrument connections appear as short ¾"–2" lines off the main line. On isometrics the forged fitting (elbow, tee, coupling, union, cap, plug, swage) is drawn with SW or THD weld / thread marks and called up in the bill of materials. *A short NPS ≤ 2 branch with a valve and cap or plug (vent / drain) on a P&ID is made of these fittings. Class 3000 / 6000 comes from the piping class.* | SW, THD | Piping class / small-bore bill of materials (ASME B16.11, MSS SP-83 / SP-95): Fitting type → `kind`; End connection → `end`; Nominal size → `nps`; Reduced size (swage) → `smallNps`; Pressure class → `pressureClass`; Pipe schedule → `schedule` |
| `expansion-joint` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/expansion-joint.svg) | A short section of the line drawn with a zig-zag (convoluted) outline between two flange bars; tie rods, hinges or gimbals are noted as EJ type, often tagged EJ or XJ. *Zig-zag outline in the line = bellows; a flexible hose is drawn as a wavy line. Found on exhaust ducts, cooling water, compressor and turbine connections.* | EJ, XJ | Expansion joint datasheet (EJMA): Joint type → `kind`; Nominal size → `nps`; Flange rating → `rating`; Convolutions → `convolutions`; Internal liner → `liner`; External cover → `cover` |
| `flexible-hose` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/flexible-hose.svg) | A wavy (sinusoidal) line between two end connections, sometimes with "FH" or the hose type noted; drilling rotary hoses and loading hoses are drawn the same way. *Wavy line = flexible hose; a zig-zag outline = bellows expansion-joint. Some legends tag hoses FH, which clashes with fire hydrants.* | HOSE | Hose assembly datasheet (ISO 10380 / EN 14585-1; API 16C rotary): Hose type → `kind`; Nominal size → `nps`; End rating → `rating`; Assembly length → `length`; Minimum bend radius → `bendRadius` |
| `hammer-union` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/hammer-union.svg) | A union symbol (two short bars with a third bar between them) in the line, with the figure number (e.g. Fig 1502) noted; well-test and frac schematics show one at every temporary flowline joint. *A flanged joint has two bars only. Figure numbers are not interchangeable (1502 vs 602 vs 2002 pressure ratings), so read the note.* | UN | Temporary flowline equipment list (union figure number, API 6A service): Nominal size → `nps`; Figure number → `figure` |
| `insulating-joint` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/insulating-joint.svg) | Two heavy bars across the line with a gap and a zig-zag or hatch between them, labelled IJ or IK (insulating kit), at the boundary between a cathodically protected pipeline and topsides or plant piping. *Found where a pipeline or riser meets the plant. Plain double bars are an ordinary flanged joint; a monolithic IJ is a weld-in item, an insulating gasket kit is a flange pair with an IK note.* | IJ, IK | Insulating joint datasheet (ISO 15589-1, NACE SP0286): Variant → `variant`; Nominal size → `nps`; Pressure class → `rating`; Pipe schedule → `schedule`; Tag number → `tag` |
| `rupture-disc` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/rupture-disc.svg) | A curved disc (arc) between two flange bars across the relief line, usually vertical with the inlet below, tagged PSE with the burst pressure; often fitted under a PSV with a pressure gauge or switch between them. *An arc between flange bars with no spring = rupture disc; a spring zig-zag = PSV. A disc under a PSV forms a combination device; the PI / PSH in the space between detects a leak or burst.* | RD, BD, PSE, PI, PSH | Rupture disc datasheet (ISO 4126-2 / API 520 Part I): Nominal size → `nps`; Flange rating → `rating`; Burst pressure → `burst`; Holder with flanges → `flanges`; Burst indicator → `indicator`; Tag number → `tag` |
| `restriction-orifice` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/restriction-orifice.svg) | A plate across the line (one bar, or a bar with the bore gap at the centre) between two flange bars, tagged RO or FO with the bore size, and no transmitter or taps; multi-stage ROs show several plates in a row. *With two taps to an FT bubble it is an orifice-flowmeter; without taps it is a restriction orifice. Common downstream of a BDV, in minimum-flow bypasses and on purge lines.* | RO, FO, RO | Restriction orifice datasheet (ASME MFC-14M / ISO 5167-2 plate geometry): Line size → `nps`; Flange rating → `rating`; Number of stages → `stages`; Bore ratio (d/D) → `beta`; Supplied with flanges → `flanges`; Tag number → `tag` |
| `steam-trap` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/steam-trap.svg) | A small square (or circle) in the condensate line marked T or ST, often preceded by a strainer and followed by a check valve and a test valve, at the low point of a steam line. *Box with T on a steam or condensate line = steam trap. Some legends tag traps TR, which clashes with transformer tags.* | ST | Steam trap datasheet (ISO 6704 / ISO 6554): Trap type → `kind`; Nominal size → `nps`; End connection → `ends`; Pressure class → `rating`; Integral strainer → `strainer`; Test valve → `testValve`; Tag number → `tag` |
| `drain-hub` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/drain-hub.svg) | A funnel (V or trapezoid) open at the top with the drain pipe leaving the bottom to the open-drain (OD) header; drawn below the vents and drains of equipment that discharge into it. *A funnel feeding an OD line = open drain hub or tundish. Closed drains (CD) are piped directly with no funnel.* | DH, TD | Open drain item schedule (ISO 13702 / API RP 14C drain systems): Type → `kind`; Outlet size → `nps`; Height → `height`; Bowl depth → `depth`; Cover → `cover` |
| `pipe-spool` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/pipe-spool.svg) | A solid line labelled with its line number (size-service-number-class-insulation, e.g. 8"-PG-2101-D6A-N); flanged joints appear as short double bars across the line. Insulation is marked by the H / IH suffix or a dashed outline along the line. *Process lines are thick solid; utility and minor lines thinner; instrument signal lines are dashed (electrical) or with hash marks (pneumatic). Each line number between two nozzles becomes one spool run.* |  | Line list / piping class (ASME B31.3, B36.10): Nominal size → `nps`; Wall schedule → `schedule`; Flange rating (from class) → `rating`; End connection → `ends`; Insulation → `insulated`; Service code → `service` |
| `elbow` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/elbow.svg) | On P&IDs a change of direction is just a corner in the line; elbows are only drawn on isometrics and GA drawings, as a bend or a corner with a short tick at each weld. *Take the angle and radius (LR / SR) from the isometric or the piping class, not the P&ID. Treat a P&ID corner as an elbow only when building a 3D route.* |  | Piping class / isometric bill of materials (ASME B16.9): Nominal size → `nps`; Wall schedule → `schedule`; Angle → `angle`; Radius (LR / SR) → `radius`; End connection → `ends`; Flange rating → `rating`; Service code → `service` |
| `tee` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/tee.svg) | A branch line meeting a run line; a dot at the junction confirms a connection (lines crossing without a dot or with a gap / hop are not connected). *Reducing tees are shown by the different line sizes of run and branch. Crossing lines without a dot are not a tee. On isometrics the tee is drawn with weld ticks.* |  | Piping class / isometric bill of materials (ASME B16.9): Run size → `nps`; Branch size → `branchNps`; Wall schedule → `schedule`; End connection → `ends`; Flange rating → `rating`; Service code → `service` |
| `reducer` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/reducer.svg) | A trapezoid in the line, the large end facing the larger pipe, with the two sizes written beside it (e.g. 8"×6"). Eccentric reducers have one flat side, noted FOT (flat on top) or FOB (flat on bottom). *A size change at a valve or pump nozzle is often shown only by the size note. Eccentric FOT reducers sit on pump suctions.* |  | Piping class / isometric bill of materials (ASME B16.9): Large end size → `nps`; Small end size → `smallNps`; Wall schedule → `schedule`; Type (concentric / eccentric) → `kind`; Flat side → `flat`; End connection → `ends`; Flange rating → `rating`; Service code → `service` |
| `flanged-joint` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/flanged-joint.svg) | Two short parallel bars across the line (a flange pair), sometimes with a gap between them; at a nozzle only one bar is drawn against the equipment. *Two bars with a filled or open paddle between them, or with a figure-8 drawn beside them on a short stem, is a spectacle blind or spade (not a plain joint); two bars with taps and an FE tag is an orifice flange pair. Spec breaks (class changes) are marked at a flange with the two class codes.* |  | Piping class (ASME B16.5 / B16.47 flanges, B16.20 gaskets): Nominal size → `nps`; Flange rating → `rating`; Wall schedule → `schedule`; Tag number → `tag` |
| `blind-flange` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/blind-flange.svg) | A line ending in a flange bar followed by a thicker solid bar (or a filled half-circle cap): a blinded end or spare connection. *A single solid bar across the line between two flange bars is a spade / blind in the line; a figure-8 is a spectacle blind. A line ending with a plain dome is a pipe cap (welded), not a blind.* |  | Piping class (ASME B16.5 / B16.47): Nominal size → `nps`; Flange rating → `rating`; Wall schedule → `schedule`; Tag number → `tag` |
| `spectacle-blind` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/spectacle-blind.svg) | A figure-8 drawn across the line between two flange bars: one circle filled (solid blind) and one open (spacer ring). The filled half on the line means the line is blinded (normally closed); the open half on the line means it is open. *Note NO / NC (or SO / SC) beside it for the normal position. Many legends draw the figure-8 beside the flange pair on a short stem instead of across the line: the circle next to the stem is the half in the line (open ring = open, blank = closed), and the blank may be hatched or drawn as concentric circles. A single filled paddle is a spade; a single open ring is a spacer.* | SB | Piping class / special item datasheet (ASME B16.48): Nominal size → `nps`; Flange rating → `rating`; Normal position (NO / NC) → `state`; Include flanges → `flanges` |
| `y-strainer` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/y-strainer.svg) | A Y-shaped leg slanting down from the line with a dashed line inside it for the screen, sometimes tagged SP / Y-STR with a blow-down valve on the end of the leg. *A basket or temporary cone strainer is drawn as a box or cone in the line with a dashed screen. A PDI / PDT across it monitors blockage. ISA codes here: PDI = across.* | SP, STR, PDI | Special piping item datasheet (ASME B16.34): Nominal size → `nps`; Flange rating → `rating`; Screen mesh → `mesh`; Blow-down valve → `blowdown` |
| `basket-strainer` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/basket-strainer.svg) | A pot-shaped body in the line (inlet and outlet near the top) with a dashed U-shaped basket inside and a bolted cover on top; often a PDI / PDT across it. *A Y-shaped leg is a y-strainer; a cone in the line is a temporary strainer. Twin (duplex) basket strainers are two pots with a changeover valve.* | SP, STR, PDI, PDT | Strainer datasheet (ASME VIII-1 / ASME B31.3): Nominal size → `nps`; Flange rating → `rating`; Screen mesh → `mesh`; Cover davit → `davit`; Tag number → `tag` |
| `pipe-support` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/pipe-support.svg) | On isometrics and GAs: a mark at the support point with its type code (shoe, guide G, line stop LS, anchor A, dummy leg DL, trunnion) and number; in section, the pipe resting on a shoe on a steel member or post. *Not on P&IDs. An anchor is often drawn as a cross on the pipe; a guide as two short bars either side; a shoe as a small rectangle under the pipe.* |  | Pipe support schedule (MSS SP-58 / ASME B31.3): Support type → `type`; Pipe size → `nps`; Support height → `height`; Insulated line → `insulated` |
| `sight-glass` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/sight-glass.svg) | A circle in the line between two flange bars, often with a small flapper or ball drawn inside, tagged FG (flow glass / sight flow indicator). *A circle in the line tagged FG is a sight glass; an LG on a vessel is a level gauge; a circle with M is a mag meter or motor.* | SG, FG | Sight flow indicator datasheet (ASME B16.5 / B31.3): Nominal size → `nps`; Flange rating → `rating`; Indicator → `indicator` |
| `utility-station` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/utility-station.svg) | A group of utility drops (plant air UA, utility water UW, nitrogen N) each with an isolation valve, a check valve and a hose connection (small triangle or coupling) at the end, boxed or noted "US-xx" on the utility P&ID. *Usually shown once in detail on a typical sheet and then as a small labelled circle or box at each location on layouts.* | US, UST | Utility station schedule (NORSOK L-002, ISO 14726 colour codes): Plant air → `air`; Utility water → `water`; Nitrogen → `nitrogen`; Tag number → `tag` |
| `gasket` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/gasket.svg) | Not drawn on P&IDs; on isometrics and joint details it is the thin element between two flange faces (a filled strip in section), called up in the bill of materials by type (SW, RTJ, sheet). *Type follows the piping class: spiral-wound for RF flanges, RTJ ring for ring-joint flanges (high pressure), sheet for FF / low-pressure utility.* | GSK | Piping class / gasket specification (ASME B16.20 / B16.21): Nominal size → `nps`; Pressure class → `rating`; Gasket type → `type`; Winding material → `winding`; Filler → `filler`; Ring type (RTJ) → `ring`; Thickness → `thickness` |
| `stud-bolt-set` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/stud-bolt-set.svg) | Not drawn on P&IDs; in joint details, studs are lines through both flanges with a hex nut at each end, specified in the bill of materials by number, diameter and length. *Quantity and size come from ASME B16.5 tables for the NPS and class; coating from the piping or coating specification.* | STUD | Piping class / bolting specification (ASME B16.5, ASTM A193 B7 / A194 2H): Nominal size → `nps`; Pressure class → `rating`; Coating → `coating` |
| `pipe-clamp` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/pipe-clamp.svg) | Not on P&IDs. On support drawings and isometrics a hanger is marked at the support point with its type (e.g. a rod hanger with a clamp, MSS type 3 or 4), and in detail the pipe circle is shown gripped by the clamp straps hanging from a rod. *A clamp hanging on a rod is a hanger; a shoe on steel is a pipe-support. Riser clamps carry vertical pipe at floor penetrations.* | HGR | Pipe support schedule (MSS SP-58 / SP-69): Clamp type → `type`; Pipe size → `nps`; Hanger rod length → `rod`; Finish → `finish` |
| `gas-turbine-generator` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/gas-turbine-generator.svg) | Gas turbine drawn as a narrowing trapezoid (compressor), a small combustor box with the fuel line into it, and a widening trapezoid (turbine) with the exhaust leaving, coupled by the shaft to a circle with G (generator). *On electrical single-line diagrams only the generator circle with G and ~ appears. A turbine coupled to a compressor instead of G is a turbine-driven compressor (centrifugal-compressor with driver gas-turbine). A box marked DE with G is a diesel generator.* | GT, G | API 616 gas turbine datasheet (+ IEC 60034-3 generator): Rated output → `mw`; Fuel system → `fuel`; Fuel gas connection size → `fuelNps`; Flange rating → `rating`; Exhaust stack height → `stackHeight`; Tag number → `tag` |
| `centrifugal-compressor` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/centrifugal-compressor.svg) | Trapezoid (wide end = suction, narrow end = discharge) with the driver on the shaft: a circle with M for a motor, or a gas turbine drawn as a second, reversed trapezoid. Anti-surge recycle and a recycle valve usually loop from discharge back to suction. *Trapezoid = dynamic compressor. A trapezoid narrowing the other way, coupled to a generator or compressor, is a turbine (or an expander). A rectangle with a piston is a reciprocating compressor; two meshing rotors mean a screw compressor.* | K, C | API 617 centrifugal compressor datasheet: Suction nozzle size → `suctionNps`; Discharge nozzle size → `dischargeNps`; Flange rating → `rating`; Driver rated power → `mw`; Casing type → `casing`; Nozzle orientation → `nozzles`; Driver type → `driver`; Tag number → `tag` |
| `reciprocating-compressor` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/reciprocating-compressor.svg) | Cylinder (rectangle) with a piston and rod inside, the rod running to a crank; suction usually into the top and discharge out of the bottom, with suction and discharge pulsation bottles drawn as small horizontal vessels on each nozzle. *Multi-stage machines show one cylinder per stage with interstage coolers and scrubbers between them. A trapezoid is a centrifugal compressor.* | K, C | API 618 reciprocating compressor datasheet: Number of throws → `throws`; Cylinder bore → `bore`; Driver rated power → `kw`; Suction nozzle size → `suctionNps`; Discharge nozzle size → `dischargeNps`; Flange rating → `rating`; Tag number → `tag` |
| `screw-compressor` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/screw-compressor.svg) | Casing outline with two meshing rotors (two overlapping circles or intermeshing helices) inside, driver on the shaft. Packaged instrument-air or gas-boost units are usually shown inside a dashed package boundary with the oil separator and cooler. *Two rotors = rotary screw (or lobe) compressor. A trapezoid is centrifugal; a piston in a cylinder is reciprocating. Oil-free air packages (instrument-air-package) use the same compressor symbol inside a larger package.* | K, C | API 619 rotary-type positive displacement compressor datasheet: Driver rated power → `kw`; Service → `service`; Acoustic enclosure → `enclosure`; Inlet nozzle size → `inletNps`; Outlet nozzle size → `outletNps`; Flange rating → `rating`; Tag number → `tag` |
| `diesel-generator` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/diesel-generator.svg) | Rectangle for the diesel engine (marked D or DE) coupled to a circle with G and ~ for the alternator. On P&IDs it appears with its diesel (DF) supply line from a day tank and an exhaust line. *G with a turbine trapezoid is a gas-turbine-generator. DE coupled to a pump is a diesel-firewater-pump.* | G, EDG, DG | Generating set datasheet (ISO 8528 / ISO 3046, NFPA 110): Rated output (kWe) → `kw`; Enclosure → `enclosure`; Fuel connection size → `fuelNps`; Tag number → `tag` |
| `gas-turbine-compressor` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/gas-turbine-compressor.svg) | A gas turbine (narrowing trapezoid, combustor box with the fuel line, widening trapezoid) coupled by its shaft to a compressor trapezoid, wide end at suction; anti-surge recycle and blowdown lines around the compressor. *A compressor coupled to a motor circle with M is the motor-driven version (centrifugal-compressor). A turbine coupled to a G circle is a gas-turbine-generator.* | K, C, GT | API 616 gas turbine + API 617 compressor datasheets: Suction nozzle size → `suctionNps`; Discharge nozzle size → `dischargeNps`; Flange rating → `rating`; Turbine rated power → `mw`; Casing type → `casing`; Nozzle orientation → `nozzles`; Tag number → `tag` |
| `vertical-turbine-pump` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/vertical-turbine-pump.svg) | Pump set drawn vertically: motor (circle with M) on top, discharge head with a side outlet at deck level, and a long column hanging down into a caisson or sump with the pump bowls at the bottom, often below a sea-level mark. *Seawater lift and firewater pumps on offshore platforms are this type. A diesel driver box instead of M means diesel-firewater-pump. Some legends draw only a pump circle with "VS1" or "caisson" written beside it.* | P | API 610 vertical pump datasheet (VS1): Driver rated power → `kw`; Discharge nozzle size → `dischargeNps`; Flange rating → `rating`; Setting depth → `depth`; Caisson diameter → `caissonDiameter`; Number of stages → `stages`; Tag number → `tag` |
| `diesel-firewater-pump` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/diesel-firewater-pump.svg) | Pump symbol (or vertical caisson pump) coupled to a rectangle marked D, DE or "diesel" for the engine driver, on a firewater (FW) line feeding the ring main, often inside a dashed pump-house boundary. *Same pump circle as any centrifugal pump: the diesel driver box, the FW line service and the firewater pump title decide it. An electric firewater (jockey) pump has M instead of DE.* | P, FWP | Fire pump datasheet (NFPA 20, API 610 VS1 / BB1): Pump type → `pumpType`; Driver rated power → `kw`; Discharge nozzle size → `dischargeNps`; Suction nozzle size → `suctionNps`; Flange rating → `rating`; Setting depth → `depth`; Caisson diameter → `caissonDiameter`; Number of stages → `stages`; Tag number → `tag` |
| `between-bearings-pump` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/between-bearings-pump.svg) | Same centrifugal pump circle (tangential discharge, side suction), here with the driver drawn as a circle with M on the shaft. High-head water injection or export duty, often noted "multistage" or "BB3". *The symbol does not show between-bearings or multistage construction; pick this component when the title, datasheet or duty says multistage / BB3 / high head (e.g. water injection, pipeline booster). Otherwise use centrifugal-pump.* | P | API 610 centrifugal pump datasheet (BB3): Suction nozzle size → `suctionNps`; Discharge nozzle size → `dischargeNps`; Flange rating → `rating`; Driver rated power → `kw`; Number of stages → `stages`; Lube oil console (API 614) → `lubeConsole`; Tag number → `tag` |
| `vertical-inline-pump` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/vertical-inline-pump.svg) | Pump circle with suction and discharge on the same straight centreline through the casing (in-line), and the motor drawn above it on a vertical shaft. *Many legends draw it as the normal centrifugal pump circle; the in-line nozzles and vertical motor are the clue when shown. Confirm OH3 / "vertical in-line" on the datasheet.* | P | API 610 centrifugal pump datasheet (OH3): Suction nozzle size → `suctionNps`; Discharge nozzle size → `dischargeNps`; Flange rating → `rating`; Driver rated power → `kw`; Tag number → `tag` |
| `reciprocating-pump` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/reciprocating-pump.svg) | Pump circle with a piston (a short thick bar) and rod inside, the rod leaving to a crank; suction in at the bottom and discharge out at the top, often with pulsation dampeners drawn as small domes on both lines. *A piston, plunger or crank inside the circle marks positive displacement. An adjustable-stroke arrow through it means a metering pump. Legends vary: some use a rectangle with a piston instead of a circle.* | P | API 674 reciprocating pump datasheet: Number of plungers → `plungers`; Driver rated power → `kw`; Suction nozzle size → `suctionNps`; Discharge nozzle size → `dischargeNps`; Suction flange rating → `suctionRating`; Discharge flange rating → `rating`; Tag number → `tag` |
| `metering-pump` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/metering-pump.svg) | Small pump circle with a curved diaphragm line inside and a diagonal arrow through it (adjustable capacity), on a chemical injection (CI) line, usually inside a chemical injection package boundary. *The diagonal arrow (variable stroke) and the small CI / MI line size tell it from a centrifugal pump. Several identical heads in a row inside a dashed box = a chemical-injection-skid.* | P | API 675 controlled-volume pump datasheet: Suction connection size → `suctionNps`; Discharge connection size → `dischargeNps`; Suction flange rating → `suctionRating`; Discharge flange rating → `rating`; Driver rated power → `kw`; Stroke length setting → `stroke`; Tag number → `tag` |
| `electric-motor` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/electric-motor.svg) | Circle with M (IEC: M with 3~ underneath for a three-phase AC motor), drawn coupled to the driven machine on P&IDs and hanging from a feeder on single-line diagrams. *Circle with G is a generator. A circle with M on top of a valve stem is a motor actuator (MOV), not a separate motor. A circle with M inside a square is used by some legends for a motor-driven package.* | PM, KM | Electric motor datasheet (IEC 60034-1 / IEC 60072): Rated power → `kw`; Number of poles → `poles`; Anti-condensation heater → `heater`; Terminal box position → `terminalBox`; Tag number → `tag` |
| `centrifugal-fan` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/centrifugal-fan.svg) | Circle (scroll) with a wide rectangular outlet duct leaving tangentially and curved blades or a hub drawn inside; inlet through the centre. Axial fans are drawn as a propeller (bow-tie) inside a circle or duct. *Looks like a pump but the outlet is a wide duct and it sits on HVAC ducting (often drawn double-line) rather than a pipe. Air cooler fans are part of air-cooled-exchanger.* | EF, SF, FN | Fan datasheet (AMCA 99 / ISO 13349): Impeller diameter → `wheelDiameter`; Motor rated power → `kw`; Discharge orientation → `outlet`; Tag number → `tag` |
| `progressive-cavity-pump` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/progressive-cavity-pump.svg) | Rotary pump outline (a long rounded casing or circle) with a helical rotor drawn as a wavy line inside, suction into the top of the suction housing and discharge out of the end; driver on the shaft. *Many legends use the general rotary PD pump symbol with "PC" or "progressive cavity" beside it. Used for viscous, sandy or shear-sensitive liquids (drains, sludge, crude transfer).* | P | API 676 rotary pump datasheet: Suction nozzle size → `suctionNps`; Discharge nozzle size → `dischargeNps`; Flange rating → `rating`; Driver rated power → `kw`; Number of stages → `stages`; Tag number → `tag` |
| `submersible-pump` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/submersible-pump.svg) | A pump hanging in a caisson below sea level with the motor (circle with M) BELOW the pump bowls at the bottom of the string, the discharge riser going up to the top plate and a power cable alongside. *Motor at the bottom = submersible; motor on top of the deck = vertical-turbine-pump (line shaft). Some legends draw only a pump circle in the caisson with "ESP" or "submersible" written.* | P | Submersible pump datasheet (API 610 VS family): Motor rated power → `kw`; Discharge size → `dischargeNps`; Flange rating → `rating`; Setting depth → `depth`; Caisson diameter → `caissonDiameter`; Tag number → `tag` |
| `centrifugal-pump` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/centrifugal-pump.svg) | Circle with the discharge leaving tangentially from the top, suction entering the centre from the side. Often a small triangle inside pointing to the discharge, and a base line or two short legs under it. *P&IDs rarely show the API 610 type. OH2, OH3, BB3 and VS pumps can all appear as this circle: read the datasheet or the title (e.g. "multistage", "vertical inline", "caisson"). A circle with a piston or crank inside is a reciprocating pump; an arrow through the symbol means variable capacity (metering pump).* | P | API 610 centrifugal pump datasheet: Suction nozzle size → `suctionNps`; Discharge nozzle size → `dischargeNps`; Flange rating → `rating`; Driver rated power → `kw`; Number of stages → `stages`; Tag number → `tag` |
| `toxic-gas-detector` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/toxic-gas-detector.svg) | F&G layout: a gas-detector symbol (circle, sometimes a triangle) with T, TOX or the gas (H2S, CO, SO2) and the ppm set points written beside it; on C&E charts an AT bubble. *Same family as point-gas-detector: the gas name decides. Flammable detectors read % LEL; toxic detectors read ppm.* | GDT, GD, TGD, AT, AIT | Toxic gas detector datasheet (IEC 60079-29-1 / EN 45544): Target gas → `gas`; Mounting → `mount`; Mounting height → `height`; Splash guard → `splashGuard`; Tag number → `tag` |
| `acoustic-gas-leak-detector` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/acoustic-gas-leak-detector.svg) | F&G layout: a detector symbol marked U, UGLD or AGLD with its detection radius (a dashed circle, typically 5–20 m) drawn around it; sound-wave arcs on some legends. *Large coverage circles centred on a detector are ultrasonic (acoustic); flame detectors show a cone; open-path detectors a beam line.* | UGLD, AGLD, GD | Ultrasonic gas leak detector datasheet (IEC 60079-1 / -11): Mounting → `mount`; Mounting height → `height`; Array head → `array`; Tag number → `tag` |
| `hydrogen-detector` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/hydrogen-detector.svg) | F&G or HVAC layout: a gas-detector symbol with H2 written beside it, placed at the ceiling high point of battery rooms, UPS rooms and electrolyser enclosures; on C&E charts an AT bubble with the % LEL set points. *Hydrogen detectors sit at ceiling level (H2 is lighter than air); hydrocarbon point detectors in process areas are usually lower.* | GDH, GD, AT | Gas detector datasheet (IEC 60079-29-1; IEC 62485-2 battery rooms): Mounting → `mount`; Drop rod length → `drop`; Mounting height → `height`; Sensor type → `sensor`; Collector cone → `collector`; Tag number → `tag` |
| `aspirating-smoke-detector` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/aspirating-smoke-detector.svg) | A detector box marked ASD (or VESDA) with a sampling pipe running across the ceiling plan and the sampling holes marked as dots or short ticks along it. *A pipe line with sampling holes from a box = aspirating system; point smoke detectors are individual circles with S.* | ASD, SD, VESDA | Aspirating smoke detector design (EN 54-20): Unit mounting height → `height`; Pipe height → `pipeHeight`; Pipe length → `length`; Hole spacing → `spacing`; Branches → `branches`; Tag number → `tag` |
| `beam-smoke-detector` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/beam-smoke-detector.svg) | A transceiver symbol at one end and a reflector (square with a cross) at the other, joined by a beam line (often double-headed or a pair of lines) across a large open space. *Reflector at one end (no receiver electronics) = reflective beam smoke detector. A transmitter / receiver pair with a single beam on a process area is an open-path gas detector.* | BSD, SD | Beam smoke detector datasheet (EN 54-12): Mounting → `mount`; Beam length → `separation`; Mounting height → `height`; Tag number → `tag` |
| `pa-loudspeaker` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/pa-loudspeaker.svg) | IEC loudspeaker: a small rectangle with a flared trumpet (trapezoid) opening from it, drawn at each speaker position on the PA/GA layout with its power tap (e.g. 15 W) and aiming direction. *An alarm sounder is drawn as a bell or horn; a combined beacon and sounder is alarm-beacon. PA loudspeakers carry a wattage note.* | SPK | PA/GA loudspeaker datasheet (EN 54-24, IEC 60079-1): Style → `style`; Mounting → `mount`; Mounting height → `height`; Aiming tilt → `tilt`; Aiming pan → `pan`; Power tap → `power`; Tag number → `tag` |
| `emergency-light` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/emergency-light.svg) | Lighting layout: the luminaire outline (a long rectangle for a linear fitting, a circle for a bulkhead) with a filled mark, a cross or E for the emergency / self-contained battery version and the duration (e.g. 3 h) beside it. *The filled mark or E distinguishes emergency fittings from normal luminaires on the same drawing. Escape signs are drawn separately (escape-sign).* |  | Emergency luminaire schedule (IEC 60598-2-22, EN 1838): Style → `style`; Mounting → `mount`; Mounting height → `height`; Length → `length`; Tag number → `tag` |
| `escape-sign` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/escape-sign.svg) | On escape route plans: a small sign rectangle showing the ISO 7010 emergency exit or assembly point symbol with a direction arrow, at each change of direction along the escape route; route arrows drawn along the walkways. *Only on escape and safety plans. Muster / assembly points use the square E007-type sign; exits use the rectangular sign with an arrow.* |  | Safety sign schedule (ISO 7010, ISO 3864-1, ISO 16069): Sign symbol → `symbol`; Direction arrow → `arrow`; Lighting → `lighting`; Mounting → `mount`; Mounting height → `height`; Legend → `legend`; Tag number → `tag` |
| `emergency-telephone` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/emergency-telephone.svg) | Telecom or escape layout: a telephone symbol (box with a handset) at the phone position, labelled EMERGENCY or with its extension; booths and acoustic hoods noted. *Only on telecom and escape layouts. A box with only a push-button is a manual call point.* |  | Telephone station datasheet (IEC 60079-1): Enclosure → `enclosure`; Mounting → `mount`; Colour → `colour`; Mounting height → `height`; Ringing beacon → `beacon`; ISO 7010 sign → `sign`; Tag number → `tag` |
| `fire-hydrant` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/fire-hydrant.svg) | Fire-protection layouts: a hydrant symbol (a circle with outlet stubs, or a pillar with two side outlets) on the underground firewater main, tagged H or FH; on the firewater P&ID a branch off the ring with an isolation valve. *A riser with a nozzle barrel is a fire monitor; a reel is a hose reel. Pillar hydrants are onshore; offshore uses hose stations and monitors on the ring main.* | FH, HYD | Fire hydrant datasheet (AWWA C502 / EN 14384): Inlet size → `nps`; Pressure class → `rating`; Outlets → `outlets`; Bury depth → `bury`; Tag number → `tag` |
| `deluge-nozzle` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/deluge-nozzle.svg) | On deluge layouts and isometrics: a short drop from the deluge pipe ending in a nozzle (small open cone or triangle) with its spray pattern; closed sprinkler heads are a circle with a dot. The nozzle type and K-factor are tabulated. *Open nozzle (no bulb) = deluge; a sprinkler head (bulb) is drawn as a filled circle or circle with a dot. On P&IDs a deluge network is one line after the deluge valve with "nozzles" noted.* | NZ | Water-spray nozzle schedule (NFPA 15 / NFPA 13): Head type → `kind`; Connection size → `nps`; Pressure class → `rating`; Drop length → `drop`; Spray angle → `angle`; Bulb temperature rating → `temperature`; Tag number → `tag` |
| `breathing-apparatus-cabinet` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/breathing-apparatus-cabinet.svg) | Safety equipment layouts: a cabinet rectangle with a BA mark or a cylinder outline, located at muster points, the CCR and H2S-risk areas, with the number of sets noted. *Only on safety equipment plans. A cabinet with a cross is a first-aid station; a cabinet with FE is an extinguisher.* | BA, SCBA | Safety equipment schedule (EN 137 / SOLAS FSS Code ch. 3): Number of sets → `sets`; Mounting → `mount`; Colour → `colour`; ISO 7010 sign → `sign`; Tag number → `tag` |
| `first-aid-station` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/first-aid-station.svg) | Safety equipment layouts: a square with a cross (the first-aid sign) at the station, with a stretcher noted where provided. *Only on safety equipment plans. The cross outline tells it from other cabinets.* | FA | Safety equipment schedule (ISO 7010, EN 13976 stretchers): Stretcher → `stretcher`; Mounting → `mount`; ISO 7010 sign → `sign`; Tag number → `tag` |
| `lifejacket-box` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/lifejacket-box.svg) | Escape and lifesaving plans: a box (rectangle) with a lifejacket outline or LJ mark at each muster station and lifeboat embarkation point, with the number of jackets stored written beside it. *Only on lifesaving appliance plans. A ring is a lifebuoy (life-ring); a boat outline is a lifeboat.* |  | Lifesaving appliance schedule (SOLAS LSA Code 2.2): Number of lifejackets → `capacity`; Colour → `colour`; Tag number → `tag` |
| `fire-blanket` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/fire-blanket.svg) | Safety equipment layouts: a small rectangle marked FB (fire blanket) on the wall of galleys, workshops and laboratories, sometimes with the pull tabs drawn below. *Only on safety equipment plans. FE marks an extinguisher; HR a hose reel.* | FB | Safety equipment schedule (EN 1869): Size → `size`; Mounting → `mount`; Mounting height → `height`; ISO 7010 sign → `sign`; Tag number → `tag` |
| `point-gas-detector` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/point-gas-detector.svg) | On F&G layouts: a circle (or hexagon / triangle on some legends) with G, GD or the gas (HC, H2S, H2) inside or beside it, placed at the detector position with its tag. On cause & effect and some P&IDs it is an AT / GD bubble with the gas and LEL set points written beside it. *Point detectors are single symbols; open-path detectors are a pair joined by a beam line. Toxic (H2S, CO) detectors use the same symbol with the gas name; a separate toxic-gas-detector component covers electrochemical cells.* | GD, GDH, GDT, AT, AE | Gas detector datasheet (IEC 60079-29-1 / -29-2): Mounting → `mount`; Mounting height → `height`; Sensor type → `sensor`; Target gas → `gas`; Sunshade / deluge hood → `sunshade`; Integral junction box → `junction`; Tag number → `tag` |
| `flame-detector` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/flame-detector.svg) | A detector symbol (circle with F or FD, or a small triangle) with a wedge or cone drawn from it showing the field of view, aimed into the area it covers; the tilt angle is often written beside it. *The cone of vision is the giveaway. A pair of symbols joined by a beam line is an open-path gas detector. ISA uses B (burner / combustion) for flame: BE / BT / BSH on some P&IDs.* | FD, IR3, UV/IR, BE, BT | Flame detector datasheet (EN 54-10 / FM 3260): Mounting → `mount`; Mounting height → `height`; Tilt (down) → `tilt`; Pan → `pan`; Weather hood → `hood`; Tag number → `tag` |
| `open-path-gas-detector` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/open-path-gas-detector.svg) | Two symbols, a transmitter and a receiver, at the two ends of a straight dashed beam line across the area, often labelled OGD with the path length and LEL·m set points. *The beam line between a pair of symbols is the clue; a single symbol with a cone is a flame detector. Some legends draw an arrow from transmitter to receiver.* | OGD, OPGD, GD, AT | Open-path gas detector datasheet (IEC 60079-29-4): Mounting → `mount`; Path length → `separation`; Mounting height → `height`; Tag number → `tag` |
| `manual-call-point` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/manual-call-point.svg) | A square with a filled circle (or a small square) in the middle, at the call point position on escape routes and exits, labelled MAC / MCP; ESD push-buttons use the same box marked ESD or with a different fill. *NFPA-style US legends draw the pull station as a square with F or a hand. On P&IDs and C&E charts a manual call point is an HS bubble feeding the F&G logic.* | MAC, MCP, ESD PB, HS, HAS | Manual call point datasheet (EN 54-11): Type → `kind`; Mounting → `mount`; Mounting height → `height`; ISO 7010 sign → `sign`; Tag number → `tag` |
| `alarm-beacon` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/alarm-beacon.svg) | On F&G and PA/GA layouts: a lamp symbol (circle with ×) with short light rays for the beacon, and a horn outline (trumpet) for the sounder, labelled with the colour and the GA / F&G status it shows. *Circle with × alone is a general lamp (lighting); the rays and colour note mark a status beacon. Sounders alone are a horn outline or a bell.* | XL, XA, YL | Visual / audible alarm device datasheet (EN 54-23 / EN 54-3): Lens colour → `colour`; Sounder → `sounder`; Mounting → `mount`; Mounting height → `height`; Flash rate → `flash`; Tag number → `tag` |
| `deluge-valve-skid` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/deluge-valve-skid.svg) | On the firewater P&ID: a deluge valve (valve body with a solenoid release box, tagged DV / XV) between two locked-open (LO) isolation valves, feeding a dry deluge pipe network drawn to the nozzles; often inside a dashed skid boundary. *Look for the firewater (FW) line, the LO marks and the dry pipe downstream. A plain ESDV on a process line is esd-valve. Some legends draw the deluge valve as a check-valve body with a clapper. ISA codes here: XY = solenoid; PSL = trip.* | DV, XV, XY, PSL | Deluge valve datasheet (NFPA 15 / EN 12259-9): Size → `nps`; Pressure class → `rating`; Isolation valves → `isolation`; Skid frame → `frame`; Tag number → `tag` |
| `fire-monitor` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/fire-monitor.svg) | On fire-protection layouts: a riser with a swivel (small circle) and a tapered nozzle barrel, sometimes with an arc showing the throw or the oscillation sector; on the firewater P&ID it is a branch off the ring main with an LO isolation valve and FM / MON tag. *A hose reel shows a drum with coiled hose; a hydrant is a riser with outlets and no barrel. Foam monitors are the same symbol with a foam (AFFF) supply.* | FM, MON | Fire monitor datasheet (EN 15767 / NFPA 15): Inlet size → `nps`; Pressure class → `rating`; Riser height → `height`; Oscillating → `oscillating`; Tag number → `tag` |
| `hose-reel` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/hose-reel.svg) | Circle with a smaller concentric circle (the drum) and the hose leaving to a nozzle, labelled HR; on the firewater P&ID a small branch off the ring main with a ball valve and HR tag. *Concentric circles = reel. A riser with a nozzle barrel is a fire monitor; a box with letters FE or a cylinder outline is an extinguisher.* | HR, FHR | Fire hose reel datasheet (EN 671-1): Reel style → `style`; Inlet size → `nps`; Pressure class → `rating`; Hose length → `hoseLength`; Tag number → `tag` |
| `safety-shower` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/safety-shower.svg) | On layouts: a shower head (dome) on a pipe with spray lines and an eyewash bowl, or a box marked SS / EW with the ISO 7010 green sign; on utility P&IDs a small potable-water branch ending in an SS tag. *Placed near chemical injection, battery rooms and laboratories. A box marked EW alone is a standalone eyewash.* | SS, EW, SSEW | Emergency shower and eyewash datasheet (ANSI Z358.1 / EN 15154): Inlet size → `nps`; Shower head height → `headHeight`; Foot treadle → `foot`; Flow alarm → `alarm`; ISO 7010 sign → `sign`; Tag number → `tag` |
| `fire-extinguisher` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/fire-extinguisher.svg) | On fire-protection layouts: a small extinguisher outline or a triangle / square with the agent letters (DP, CO2, FOAM) and size (e.g. 9 kg); wheeled units are marked W or with wheels. *Legends vary a lot; read the letters for the agent and capacity. Not shown on P&IDs.* | EXT | Portable extinguisher schedule (EN 3-7 / NFPA 10): Unit → `unit`; Agent → `agent`; Capacity → `capacity`; Quantity → `count`; Cabinet door → `door`; Mounting → `mount`; ISO 7010 sign → `sign`; Tag number → `tag` |
| `windsock` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/windsock.svg) | On helideck and platform layouts: a mast with a truncated cone (the sock) streaming from it, sometimes only a small circle at the mast position labelled WS. *Located clear of the helideck obstacle-free sector, visible from the approach. Not shown on P&IDs.* |  | Helideck windsock specification (CAP 437 / ICAO Annex 14 Vol II): Mast height → `height`; Sock length → `length`; Colour → `colour`; Lighting → `lighting`; Tag number → `tag` |
| `heat-detector` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/heat-detector.svg) | Circle (or square on NFPA-style legends) with H or HD, placed on the ceiling plan of enclosed modules or near specific equipment (turbine hoods, battery rooms); fixed-temperature or rate-of-rise noted beside it. *Letters inside the circle distinguish detector types: H heat, S smoke, F flame, G gas. On some P&IDs heat detection is a TSH bubble or a fusible-plug loop on the instrument air.* | HD, TSH, TAH | Heat detector datasheet (EN 54-5): Mounting → `mount`; Drop rod length → `drop`; Rated temperature → `rating`; Tag number → `tag` |
| `smoke-detector` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/smoke-detector.svg) | Circle (or square) with S or SD on the ceiling plan of enclosed rooms: LER, CCR, accommodation and HVAC ducts (duct detectors marked D). *Same family as the heat detector: read the letter. BS-style legends draw a smoke detector as a circle with S; NFPA-style may use a square or SD in a circle.* | SD | Smoke detector datasheet (EN 54-7): Drop rod length → `drop`; Remote indicator LED → `alarm`; Tag number → `tag` |
| `life-ring` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/life-ring.svg) | On escape and lifesaving appliance plans: a ring (two concentric circles) with four bands, at each lifebuoy station; a light or smoke signal is marked L / S beside it. *Only on escape / lifesaving plans, never on P&IDs.* |  | Lifesaving appliance schedule (SOLAS LSA Code 2.1): Mounting → `mount`; Mounting height → `height`; Light / smoke signal → `signal`; Station name → `name`; Tag number → `tag` |
| `deck-module` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/deck-module.svg) | Plan view: the deck outline with dash-dot structural grid lines (rows and columns, e.g. A–D and 1–6) and circles at the jacket leg positions; deck elevations (EL +28.000 TOS) written in the corners. *Not on P&IDs. Equipment layouts use this outline as the background; the grid labels locate equipment. A smaller framed rectangle with bracing is a module-frame.* |  | Structural design basis / deck framing drawing (ISO 19902, NORSOK N-004): Deck length → `length`; Deck width → `width`; Floor type → `floor`; Primary girder → `primary`; Secondary beam → `secondary`; Secondary spacing → `secondarySpacing`; Number of legs → `legs`; Leg spacing X → `legSpanX`; Leg spacing Z → `legSpanZ`; Leg diameter → `legDiameter` |
| `pipe-rack` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/pipe-rack.svg) | Cross-section: a portal frame (two posts and one or more tier beams) with the pipes drawn as circles resting on each tier; in plan, two parallel lines with the bent positions marked across them and the pipes as lines along the rack. *Not on P&IDs (lines there are schematic). Cable trays on the top tier appear as narrow rectangles. A single post with arms is a cable-tray support.* |  | Pipe rack design drawing (PIP STC01015): Number of bays → `bays`; Bay length → `bayLength`; Rack width → `width`; Number of tiers → `tiers`; First tier elevation → `firstTier`; Tier spacing → `tierSpacing`; Post section → `post`; Tier beam section → `beam` |
| `stair` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/stair.svg) | Plan view: a rectangle filled with parallel tread lines and an arrow along it labelled UP (or DN), often with a break line half-way. *Rungs at close spacing with a circle around them is a caged ladder seen in plan. Not on P&IDs.* |  |  |
| `ladder` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/ladder.svg) | Elevation: two stiles with rungs and hoops of the safety cage; in plan, a short pair of lines with a semicircle (the cage) against the platform edge, labelled LADDER. *A stair has an inclined flight with an UP arrow; a ladder is vertical. Not on P&IDs.* |  |  |
| `access-platform` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/access-platform.svg) | Plan view: a rectangle (often partly hatched to show grating) with the leg positions marked at the corners and the ladder or stair access drawn at one edge, labelled with its top-of-grating elevation (TOG EL +…). *On P&IDs an access platform is sometimes noted beside a valve as "accessible from platform", not drawn. A larger outline with grid lines is a deck-module.* |  | Platform / access structure drawing (ISO 14122-2/3/4): Length → `length`; Width → `width`; Top of grating height → `height`; Access → `access`; Leg section → `leg`; Frame section → `frame` |
| `jacket` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/jacket.svg) | Elevation: a tapering (battered) frame from the seabed up to the deck with horizontal levels and X or K bracing, the sea level drawn as a wave line and the mudline at the bottom; in plan, circles at the leg positions. *Not on P&IDs. Risers and conductors are drawn along the jacket face; the deck above is deck-module.* |  | Jacket structural drawing / design basis (ISO 19902, API RP 2A-WSD): Number of legs → `legs`; Water depth → `waterDepth`; Air gap → `airGap`; Leg spacing X (top) → `spanX`; Leg spacing Z (top) → `spanZ`; Leg batter → `batter`; Leg diameter → `legDiameter`; Bracing pattern → `bracing`; Conductors → `conductors`; Risers → `risers`; Riser size → `riserNps`; Riser rating → `riserRating` |
| `bridge` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/bridge.svg) | Elevation: two horizontal chords joined by a zig-zag Warren truss, with a pinned support (triangle) at one end and a sliding support (roller circle) at the other; in plan, two parallel lines between the platform outlines labelled with the bridge name. *On P&IDs a bridge appears only as off-page arrows "via bridge to RP" on lines that cross it. The sliding end is what lets the platforms move relative to each other.* |  | Bridge structural drawing (EN 1993-2): Span → `length`; Walkway width → `width`; Truss depth → `depth`; Truss type → `truss`; Cable trays → `cableTrays`; Pipe shelf → `pipeShelf`; Walkway lights → `lights` |
| `helideck` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/helideck.svg) | Plan view: an octagon (or circle) with the touchdown / positioning circle and the letter H at the centre, the D-value and maximum mass written on it, plus the obstacle-free sector chevron. *The H in a circle on an octagon is unambiguous. The helicopter refuelling package and the windsock are separate items around it.* |  | Helideck design specification (CAP 437): D-value → `dValue`; Deck height → `height`; Maximum allowable mass → `maxMass`; Installation name → `installation`; Perimeter netting → `netting`; Lighting → `lights` |
| `steel-column` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/steel-column.svg) | Plan view at a grid intersection: the column section (an H or I shape, a square for SHS, a circle for CHS) on a square base plate with anchor bolt circles, tagged with its section size. *Not on P&IDs. On framing plans columns sit on the dash-dot grid; a beam is drawn as a single line between them with its section written along it.* |  | Structural member schedule (EN 10365 / AISC 360): Section → `section`; Height → `height`; Web orientation → `web`; Pedestal height → `pedestal`; Base plate size → `plate`; Finish → `finish` |
| `steel-beam` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/steel-beam.svg) | Elevation: two parallel flange lines with end plates (or fin plates) at each end; on framing plans a single thick line between columns with the section (e.g. IPE 300, TOS EL +28.000) written along it. *Not on P&IDs. A beam drawn thicker on a plan is usually a primary girder.* |  | Structural member schedule (EN 10365 / AISC 360): Section → `section`; Length → `length`; Top of steel → `topOfSteel`; Connection → `connection`; Stiffeners → `stiffeners`; Finish → `finish` |
| `grating-panel` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/grating-panel.svg) | Plan view: an area filled with close parallel lines (the bearing bar direction), sometimes a cross-hatch, with the panel outline; solid plate is drawn plain or with a checker-plate hatch. *Only on structural and layout drawings. The hatch direction shows the span direction of the bearing bars.* |  | Grating schedule (EN ISO 14122-2 / ANSI/NAAMM MBG 531): Panel length → `length`; Panel width → `width`; Bearing bar depth → `depth`; Bearing bar pitch → `pitch`; Kick plates → `kickPlates`; Finish → `finish` |
| `handrail` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/handrail.svg) | Elevation: top rail and knee rail on posts with a toe plate at the bottom; on plans a line just inside the deck or platform edge with small post marks (or crosses), and a gate drawn as a short swing arc. *On plans it looks like a wall line; the post marks and the location at the edge identify it. Not on P&IDs.* |  | Guard-rail detail (ISO 14122-3): Length → `length`; Rail height → `height`; Self-closing gate → `gate`; Gate width → `gateWidth`; End returns → `returns`; Toe plate → `toePlate`; Finish → `finish` |
| `cable-tray` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/cable-tray.svg) | Cross-section: stacked open trays (U-channels) on cantilever arms from a post; on cable routing plans two parallel lines with the tray width and level (e.g. 600 W, TOT EL +3.2) and short diagonals or rung marks. *Only on electrical and instrument layouts. Two parallel lines with rungs in plan can be confused with a ladder; trays run along routes and carry width notes.* |  | Cable tray schedule (IEC 61537 / NEMA VE 1): Run length → `length`; Tray width → `width`; Number of tiers → `tiers`; Tier spacing → `tierSpacing`; Elevation → `elevation`; Support spacing → `supportSpacing`; Cover → `cover`; Material → `material` |
| `caisson` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/caisson.svg) | A long vertical pipe or open-bottom vessel hanging from the deck through the sea-level line, with the inlet or pump column entering at the top; labelled as seawater lift, firewater, disposal or sump caisson. *Pumps drawn inside it are vertical-turbine-pump or diesel-firewater-pump. A riser is a pipe line (with ESDV) that continues to a subsea pipeline, not an open-ended caisson.* |  | Caisson datasheet / structural drawing (NORSOK P-001, ISO 19902): Caisson size → `nps`; Length → `length`; Stick-up above deck → `stickUp`; Inlet nozzle size → `inletNps`; Vent nozzle size → `ventNps`; Flange rating → `rating`; Guide spacing → `guideSpacing`; Anodes → `anodes` |
| `module-frame` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/module-frame.svg) | Elevation: a rectangular frame with intermediate floor and X-bracing on the faces, padeyes at the top corners; on plot plans a module boundary rectangle with its tag and weight. *On P&IDs a module or package boundary is a dash-dot rectangle around the equipment it carries.* |  | Module structural drawing / weight report (ISO 19901-6, DNV-ST-N001): Length → `length`; Width → `width`; Height → `height`; Base frame section → `base`; Column section → `post`; Roof beam section → `roofBeam`; Roof deck → `roofDeck`; Bracing → `bracing`; Padeyes → `padeyes` |
| `shell-and-tube-exchanger` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/shell-and-tube-exchanger.svg) | Horizontal shell (long rectangle or capsule) with the channel head at one end and the tube bundle drawn as a line or U inside; tube-side nozzles on the channel, shell-side nozzles on the shell. Many legends draw a circle with a zig-zag through it, or two interlocking circles, for any exchanger, with the TEMA type (AES, AEU, BEM, AKT) written beside it. *The tag letter E and the TEMA type confirm it. A shell with an enlarged dome and a weir is a kettle (AKT). A box with a fan is an air cooler; a frame with many plates is a plate exchanger; two pipes with a return bend is a hairpin.* | E, HX | TEMA shell-and-tube heat exchanger specification sheet (API 660): TEMA type → `tema`; Shell inside diameter → `diameter`; Tube length → `length`; Tube passes → `passes`; Shells (stacked) → `stacked`; Design pressure → `pressure`; Flange rating → `rating`; Shell-side nozzle size → `shellNps`; Tube-side nozzle size → `tubeNps`; Insulation → `insulated`; Tag number → `tag` |
| `air-cooled-exchanger` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/air-cooled-exchanger.svg) | Rectangle (the finned-tube bundle, often with a zig-zag tube line inside) with a fan below it (forced draft) or above it (induced draft), drawn as a propeller or bow-tie on a shaft to a motor (circle with M); louvres as a row of slanted lines over the bundle. *The fan with its motor tells it from a shell-and-tube exchanger. The number of bays and fans is written beside it (e.g. 2 bays × 2 fans).* | E, EA, AC | API 661 / ISO 13706 air-cooled heat exchanger datasheet: Number of bays → `bays`; Fans per bay → `fansPerBay`; Tube length → `tubeLength`; Bay width → `bayWidth`; Tube rows → `rows`; Draft type → `draft`; Tube passes → `passes`; Louvres → `louvres`; Header type → `header`; Inlet nozzle size → `inletNps`; Outlet nozzle size → `outletNps`; Flange rating → `rating`; Fan motor power → `kw`; Tag number → `tag` |
| `plate-heat-exchanger` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/plate-heat-exchanger.svg) | Rectangle (the plate pack) crossed by several parallel lines (the plates), between a fixed frame plate and a pressure plate, with all four connections on the fixed frame end; some legends draw a box with a diagonal zig-zag. *Many parallel lines inside a compact box = plate exchanger. A solid block with channels is a PCHE.* | E, HX, PHE | Plate heat exchanger datasheet (API 662 / ISO 15547-1): Connection size → `nps`; Flange rating → `rating`; Number of plates → `plates`; Plate pitch → `pitch`; Tag number → `tag` |
| `flare-boom` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/flare-boom.svg) | On the flare P&ID: the flare header ending at a flare tip symbol (a short stack with a flame outline on top), with pilot gas and ignition lines; on layouts an inclined boom outline from the platform edge to the tip. *Inclined boom = offshore flare boom; a vertical stack from grade is a flare-stack. A stack with no flame symbol is a cold vent.* |  | Flare system datasheet (API 537, API 521 radiation): Boom length → `length`; Boom angle → `angle`; Header size → `headerNps`; Flange rating → `rating`; Number of pilots → `pilots`; Tag number → `tag` |
| `flare-stack` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/flare-stack.svg) | A tall vertical stack with a flame outline at the tip and the flare header entering at the base, often with the molecular or velocity seal drawn as a bulge below the tip and pilot lines alongside. *With a flame at the top it is a flare; without one it is a cold vent stack. A ground flare is a box or fence enclosure with burners.* |  | Flare system datasheet (API 537, API 521): Stack height → `height`; Support type → `support`; Header size → `headerNps`; Flange rating → `rating`; Number of pilots → `pilots`; Purge seal type → `seal`; Tag number → `tag` |
| `fired-heater` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/fired-heater.svg) | A box (radiant section) with a zig-zag process coil inside, burners drawn as small flames or triangles at the floor, a tapering convection section and a stack on top; the fuel gas line goes to the burners. *Zig-zag coil inside a firebox with burners = fired heater. An electric heater has a resistance element and a terminal box; a TEG reboiler is a horizontal capsule with a fire tube.* | H | API 560 / ISO 13705 fired heater datasheet: Radiant section diameter → `diameter`; Radiant height → `radiantHeight`; Stack height → `stackHeight`; Number of burners → `burners`; Number of passes → `passes`; Coil connection size → `nps`; Flange rating → `rating`; Tag number → `tag` |
| `vent-stack` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/vent-stack.svg) | A line turning up into an open-ended stack with an arrow or "to atmosphere" at the top, often with a flame arrester (box with parallel lines) at or near the tip; labelled VENT or VS-. *No flame symbol: a cold vent. An open-ended small-bore line ending in a goose-neck or "TO ATM" is just a vent connection, not a stack.* | VS | Vent stack datasheet (API 521 dispersion, ISO 16852 flame arrester): Stack height → `height`; Stack size → `nps`; Flange rating → `rating`; Support type → `support`; Flame arrester → `arrestor`; Tag number → `tag` |
| `electric-heater` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/electric-heater.svg) | A horizontal shell with a resistance element (zig-zag) drawn inside it and a terminal box on the flange end; the power supply comes from a thyristor controller and the process inlet and outlet are on the shell. *The zig-zag element plus a terminal box tells it from a shell-and-tube exchanger. On P&IDs a TIC with a TY / thyristor box and a high-temperature trip (TSHH on the element) usually accompanies it.* | H, EH | Electric process heater datasheet (IEC 60079-7 / ASME VIII-1): Rated power → `kw`; Nozzle size → `nps`; Flange rating → `rating`; Design pressure → `pressure`; Insulation → `insulated`; Tag number → `tag` |
| `hairpin-exchanger` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/hairpin-exchanger.svg) | Two parallel horizontal pipes (the legs) joined by a return bend at one end, an inner pipe shown running through both, tube-side connections at the open ends and shell-side nozzles on each leg. *The U-shaped double-pipe outline tells it from a shell-and-tube (single shell with a channel). Stacked hairpins in series are drawn as several hairpins joined by short lines.* | E, HX | Double-pipe exchanger datasheet (TEMA / ASME VIII-1): Outer pipe size → `shellNps`; Inner pipe size → `tubeNps`; Leg length → `length`; Flange rating → `rating`; Tag number → `tag` |
| `printed-circuit-heat-exchanger` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/printed-circuit-heat-exchanger.svg) | Usually a generic heat-exchanger box or rectangle with crossing flow lines and four nozzles (hot side on the ends, cold side on the faces), tagged E- and noted "PCHE" or "compact / diffusion-bonded". *There is no standard PCHE symbol: rely on the note or the datasheet. Common in gas dehydration, compression aftercooling and dew-point control where space is tight.* | E, HX | Compact heat exchanger datasheet (ASME VIII-1): Number of core blocks → `blocks`; Block length → `length`; Block width → `width`; Block height → `height`; Hot-side nozzle size → `hotNps`; Cold-side nozzle size → `coldNps`; Flange rating → `rating`; Tag number → `tag` |
| `cooling-tower` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/cooling-tower.svg) | A box (or tapering hyperbolic outline for natural draft) with a fan stack on top (propeller in a short cylinder), the hot-water distribution near the top, crossed lines for the fill, air inlets low on the sides and the cold-water basin at the bottom. *The fan on top plus fill and basin tell it from an air-cooled exchanger (tube bundle, no water basin). Onshore only.* | CT, E | Cooling tower datasheet (CTI STD-201 / ATC-105): Cells → `cells`; Cell size → `cellSize`; Fan deck height → `deckHeight`; Hot-water inlet height → `inletHeight`; Fan motor power → `kw`; Inlet size → `inletNps`; Outlet size → `outletNps`; Tag number → `tag` |
| `gate-valve` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/gate-valve.svg) | Two triangles meeting at their points (bow-tie) across the line, unfilled. A short stem with a T on top marks the handwheel; a gear operator is sometimes drawn as a small box on the stem. *A filled dot at the centre means globe; a circle means ball; a bar through the centre means butterfly. A fully black bow-tie is the same valve normally closed (NC). LO / CSO / LC / CSC written beside it are locked or car-sealed positions, not a different valve.* | HV, XV (manual) | Valve datasheet (API 600 / ASME B16.34): Size → `nps`; Pressure class → `rating`; Operator → `operator`; Tag number → `tag` |
| `ball-valve` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/ball-valve.svg) | Bow-tie across the line with an open circle at the centre where the triangle points meet. Manual valves may show a stem with a T or a lever. *Open circle = ball; filled dot = globe; plain bow-tie = gate. The same body under a square actuator with an S or a fail-close note is an ESDV / SDV / XV (esd-valve). Some legends write FB / RB beside it for full or reduced bore.* | HV | Ball valve datasheet (API 6D / ISO 17292): Size → `nps`; Pressure class → `rating`; Bore → `bore`; Ball mounting → `mounting`; Operator → `operator`; Tag number → `tag` |
| `esd-valve` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/esd-valve.svg) | Ball-valve bow-tie (circle at the centre) under a rectangular spring-return piston actuator, usually with a small box marked S (solenoid) on the actuator and "FC" beside the body. The tag bubble reads ESDV, SDV or XV. *Same symbol with FO and tag BDV is a blowdown valve. A dome actuator means a control valve; a circle with M means an MOV. Limit switches (ZSO / ZSC) and the SOV are accessories of this valve, not separate items. Some legends draw a gate body instead of a ball; the ESDV tag decides.* | ESDV, SDV, XV, SSV, ESDV, SDV, XV, ZSO, ZSC | Actuated on/off valve datasheet (API 6D / ISO 14313 + actuator sheet, IEC 61508 SIL data): Size → `nps`; Pressure class → `rating`; Tag number → `tag` |
| `blowdown-valve` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/blowdown-valve.svg) | Actuated ball valve like an ESDV (rectangular spring-return actuator, solenoid box) but marked FO, usually drawn black-filled or marked NC because it is normally closed. It sits on a line from the vessel or compressor to the flare header, often followed by a restriction orifice (RO). *Tell it from an ESDV by the FO mark, the flare (FL / BD) line it sits on and the BDV tag. The restriction orifice downstream is drawn as a pair of short bars across the line (like an orifice plate) tagged RO.* | BDV, BDV, XV, ZSO, ZSC | Blowdown valve datasheet (API 6D + actuator sheet, API 521 depressuring case): Size → `nps`; Pressure class → `rating`; Tag number → `tag` |
| `control-valve` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/control-valve.svg) | Bow-tie body with a stem up to a dome (half circle on a flat base): the spring-diaphragm actuator. A tag bubble such as LV, PV, FV, TV, PCV, LCV, FCV, TCV sits next to it, often with FC / FO / FL and a bypass globe valve drawn around it. *Dome = diaphragm actuator (control valve). A rectangle = piston actuator (usually on/off: ESDV / SDV / XV / BDV). A circle with M = MOV. A self-acting regulator (PCV with no signal line, impulse line to the pipe) uses the same body with a sensing line instead of a positioner signal.* | CV, LV, PV, FV, TV, PCV, LCV, FCV, TCV, HCV, PDV | Control valve specification sheet (IEC 60534-7 / ISA-75.25 / ISA-TR20.00.01): Body size → `nps`; Pressure class → `rating`; Tag number → `tag` |
| `pressure-safety-valve` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/pressure-safety-valve.svg) | Angle body: one triangle pointing up from the inlet below and one pointing in from the outlet on the side, meeting at a right angle, with a zig-zag spring rising from the meeting point to a short cap line. The set pressure and orifice letter (e.g. 3K4, set 42 barg) are written beside it. *The spring zig-zag tells it from a check valve or a plain angle valve. A rupture disc (PSE) is drawn as a curved disc between flanges with no spring. Size code like 3K4 means 3" inlet, K orifice, 4" outlet. The outlet line goes to the flare header (FL / RV) or to atmosphere; on a pilot-operated PSV a small pilot box is drawn beside the spring. ISA codes here: PSE = rupture disc.* | PSV, PRV, TSV, RV, PSV, PRV, TSV, PSE | Pressure relief valve datasheet (API 526 / API 520, ISA-TR20.00.01 form): Orifice letter → `orifice`; Inlet flange rating → `inletRating`; Bonnet → `bonnet`; Lifting lever → `lever`; Balanced bellows → `bellows`; Tag number → `tag` |
| `globe-valve` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/globe-valve.svg) | Bow-tie across the line with a solid black dot at the centre where the triangles meet, and a handwheel stem with a T. Often found as the bypass around a control valve or as a throttling valve. *Solid dot = globe; open circle = ball; plain bow-tie = gate. A bow-tie with a dome actuator is a control valve, which is a globe body too: the actuator decides.* | HV, HCV | Globe valve datasheet (API 623 / BS 1873 / ASME B16.34): Size → `nps`; Pressure class → `rating`; Operator → `operator`; Tag number → `tag` |
| `swing-check-valve` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/swing-check-valve.svg) | Bow-tie with one triangle filled black (the downstream half) and often a small arrow showing the free-flow direction. Some legends draw a single triangle pointing at a bar instead. *P&IDs rarely distinguish swing, dual-plate and piston checks: read the valve code in the line class or the valve datasheet. Flow is allowed in the direction the arrow (or the open triangle) points.* | CHV, NRV | Check valve datasheet (API 6D / BS 1868 / ASME B16.34): Size → `nps`; Pressure class → `rating`; Lever and counterweight → `counterweight`; Tag number → `tag` |
| `dual-plate-check-valve` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/dual-plate-check-valve.svg) | Non-return symbol (a triangle pointing at a bar across the line) squeezed between two flange marks, because the wafer body sits between the pipe flanges. Many legends just use the general check-valve bow-tie with one half filled. *Wafer-type (API 594) is usually only visible from the valve code or a "W" / "DP" note. Treat any check-valve symbol on a line ≥ NPS 3 in water or gas service with a wafer valve code as this component; otherwise use swing-check-valve.* | CHV, NRV | Wafer check valve datasheet (API 594 Type A): Size → `nps`; Pressure class → `rating`; Tag number → `tag` |
| `butterfly-valve` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/butterfly-valve.svg) | Bow-tie with a straight bar through the centre at right angles to the line (the disc), often with a dot at its middle. Older legends draw two vertical lines with a diagonal between them. *Bar through the centre = butterfly; circle = ball; filled dot = globe; two close parallel bars = knife gate. Common in seawater, cooling and firewater lines.* | HV, BFV | Butterfly valve datasheet (API 609 / ISO 5752 / EN 593): Size → `nps`; Pressure class → `rating`; Body style → `style`; Operator → `operator`; Tag number → `tag` |
| `plug-valve` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/plug-valve.svg) | Bow-tie with a small rectangle (the plug) at the centre where the triangles meet; manual plug valves show a wrench or T on the stem. *Legends vary: some draw a plug valve as a bow-tie with a filled triangle-in-circle, others as a ball valve with "P" or "PLUG". Check the legend; the valve code in the line class confirms it.* | HV | Plug valve datasheet (API 599 / API 6D): Size → `nps`; Pressure class → `rating`; Operator → `operator`; Tag number → `tag` |
| `motor-operated-valve` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/motor-operated-valve.svg) | Valve bow-tie with a stem to a circle containing M: the electric motor actuator. The tag bubble is usually MOV, XV or HV, and the valve fails in place (FL / FAI). *Circle with M = motor actuator; dome = diaphragm (control valve); rectangle = piston or spring-return (ESDV / BDV). A square with "M" is used by some legends for the same thing.* | MOV, XV, MOV, XV, HV, ZSO, ZSC | Valve datasheet (API 600) + electric actuator datasheet (ISO 5210 / IEC 60034): Size → `nps`; Pressure class → `rating`; Tag number → `tag` |
| `needle-valve` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/needle-valve.svg) | Small bow-tie on an instrument, sample, vent or drain line (NPS 1 and below) with a stem ending in a pointed needle at the seat; often unlabelled, next to a gauge or transmitter. *Usually drawn smaller than line valves and attached to instrument tubing. Many P&IDs show instrument root and manifold valves only as a generic small gate symbol, or not at all; treat them as detail unless asked.* | HV | Instrument valve datasheet (MSS SP-99 / ASME B16.34): Size → `nps`; Pressure class → `rating`; Tag number → `tag` |
| `check-valve-piston` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/check-valve-piston.svg) | Check-valve bow-tie (downstream half filled, flow arrow) with the globe-pattern dot at the centre on some legends; on most P&IDs it is drawn exactly like any check valve. *Identify it from the valve code (lift / piston check, usually small-bore or high-pressure, NPS 2 and below) rather than the symbol. Swing and dual-plate checks use the same base symbol.* | CHV, NRV | Check valve datasheet (BS 1868 / API 602 / ASME B16.34): Size → `nps`; Pressure class → `rating`; Tag number → `tag` |
| `knife-gate-valve` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/knife-gate-valve.svg) | Gate-valve bow-tie with a thin slab (two close parallel bars) drawn through the centre, standing proud of the body, and a handwheel stem. *Legends vary: some show a knife gate as a plain gate bow-tie with "KG" written beside it. A single bar through the centre is a butterfly. Typical in slurry, sand, drain and low-pressure water service.* | HV | Knife gate valve datasheet (MSS SP-81): Size → `nps`; Tag number → `tag` |
| `horizontal-separator` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/horizontal-separator.svg) | Horizontal capsule (rectangle with semi-elliptical ends). A 3-phase separator shows a weir plate inside and a water boot below; a 2-phase separator a mesh pad at the gas outlet; a KO drum is plain. *Vertical capsule = vertical-separator. Long capsule with closure door at one end = pig-launcher. A horizontal capsule with filter elements and a lower sump barrel = filter-separator.* | V, D, VA, VD | Pressure vessel datasheet (ASME VIII-1; API 12J): Service → `service`; Inside diameter → `diameter`; Length T/T → `length`; Design pressure → `pressure`; Flange rating → `rating`; Inlet nozzle size → `inletNps`; Gas outlet size → `gasNps`; Liquid outlet size → `liquidNps`; Insulation → `insulated`; Tag number → `tag` |
| `vertical-separator` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/vertical-separator.svg) | Vertical capsule (tall rectangle with elliptical heads) with a mesh pad or vane pack drawn as a hatched band near the top, gas outlet at the top, inlet on the side and liquid outlet at the bottom; scrubbers are tall and slim. *A taller capsule with trays or packing is a column; one with cartridges and a tube sheet is a cartridge filter. Scrubbers, KO drums and inlet separators all use this symbol: the internals and service decide.* | V, D, VG, VD | Pressure vessel datasheet (ASME VIII-1; API 12J): Support → `support`; Inside diameter → `diameter`; Height T/T → `height`; Design pressure → `pressure`; Flange rating → `rating`; Inlet nozzle size → `inletNps`; Gas outlet size → `gasNps`; Liquid outlet size → `liquidNps`; Insulation → `insulated`; Tag number → `tag` |
| `column` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/column.svg) | Tall vertical capsule with trays drawn as short horizontal lines alternating from the left and right walls (segmental trays), or a section with crossed diagonals for packing; overhead at the top, bottoms at the bottom, feed and reflux on the side. *Alternating tray lines or an X-crossed packed bed = column (TEG contactor, absorber, stabiliser). A shorter vessel with only a mesh pad is a vertical-separator.* | T, C, V | Column / tower datasheet (ASME VIII-1; tray or packing sheet): Internals → `internals`; Inside diameter → `diameter`; Height T/T → `height`; Number of sections → `sections`; Design pressure → `pressure`; Flange rating → `rating`; Feed nozzle size → `feedNps`; Overhead nozzle size → `overheadNps`; Bottoms nozzle size → `bottomsNps`; Reflux nozzle size → `refluxNps`; Insulation → `insulated`; Tag number → `tag` |
| `filter-separator` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/filter-separator.svg) | Horizontal vessel with filter elements (dashed vertical lines) in the first section, a vane or mesh pack in the second, a smaller liquid sump barrel below joined by downcomers, and a quick-opening closure (thick bar) at the filter end. *The second barrel underneath and the filter elements tell it from a horizontal separator. A vertical housing with cartridges is a cartridge-filter.* | V, F, S | Filter-separator datasheet (ASME VIII-1; API 12J): Inside diameter → `diameter`; Length T/T → `length`; Sump diameter → `sumpDiameter`; Design pressure → `pressure`; Flange rating → `rating`; Inlet nozzle size → `inletNps`; Outlet nozzle size → `outletNps`; Drain size → `drainNps`; Insulation → `insulated`; Tag number → `tag` |
| `cartridge-filter` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/cartridge-filter.svg) | Vertical housing on legs with a tube sheet line and the cartridges as dashed lines (or a single dashed line across for the filter medium), a quick-opening or bolted closure at the top, and a PDI / PDT across inlet and outlet. *ISO and PIP draw any filter as a vessel crossed by a dashed line; coalescers add "COALESCER". A horizontal vessel with a sump barrel is a filter-separator; a Y in the line is a y-strainer.* | F, V, PDI, PDT | Filter / coalescer datasheet (ASME VIII-1): Closure type → `closure`; Inside diameter → `diameter`; Height T/T → `height`; Design pressure → `pressure`; Flange rating → `rating`; Inlet nozzle size → `inletNps`; Outlet nozzle size → `outletNps`; Tag number → `tag` |
| `storage-tank` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/storage-tank.svg) | Flat-bottomed vertical rectangle on grade with a shallow cone (triangle) or dome roof, inlet near the top, outlet near the bottom; floating-roof tanks show the roof as a line inside the shell. Breather / PVRV and emergency vents sit on the roof. *Flat bottom on grade = atmospheric tank (API 650); a capsule with elliptical heads = pressure vessel. A circle on legs is a sphere.* | T, TK | API 650 storage tank datasheet: Roof type → `roof`; Diameter → `diameter`; Shell height → `height`; Specific gravity → `gravity`; Inlet nozzle size → `inletNps`; Outlet nozzle size → `outletNps`; Drain size → `drainNps`; Tag number → `tag` |
| `spherical-tank` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/spherical-tank.svg) | A circle standing on legs that touch it at the equator, with top and bottom nozzles; often with a water-spray (deluge) ring drawn around it. *Circle on legs = sphere. A circle on its own in a line could be a pump or an instrument bubble: check for legs and size.* | T, TK, V | Pressure storage datasheet (ASME VIII-1 / API 2510): Diameter → `diameter`; Design pressure → `pressure`; Flange rating → `rating`; Number of legs → `legs`; Inlet nozzle size → `inletNps`; Outlet nozzle size → `outletNps`; Leg fireproofing → `fireproofing`; Deluge ring → `deluge`; Tag number → `tag` |
| `air-receiver` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/air-receiver.svg) | Plain vertical capsule on legs with no internals, inlet low on one side, outlet high on the other, a PSV on top and an auto-drain at the bottom, on the instrument-air or nitrogen system. *An empty vertical vessel on an IA / UA / N2 line is a receiver; with a mesh pad and liquid outlet it is a vertical-separator.* | V, D, VA, PT, PI, PSV | Pressure vessel datasheet (ASME VIII-1): Support → `support`; Inside diameter → `diameter`; Height T/T → `height`; Design pressure → `pressure`; Flange rating → `rating`; Inlet nozzle size → `inletNps`; Outlet nozzle size → `outletNps`; Tag number → `tag` |
| `desander` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/desander.svg) | A cyclone (short cylinder over an inverted cone) with a tangential inlet on the side and the overflow out of the top, the underflow dropping through two isolation valves into a sand accumulator vessel below that is dumped periodically. *A cone over an accumulator on a well stream = desander. Produced-water hydrocyclones are horizontal multi-liner vessels without the accumulator. ISA codes here: LT = sand; XV = dump.* | V, DS, X, PDT, LT, XV | Desander datasheet (ASME VIII-1; API 6A-class end connections): Liner housing diameter → `diameter`; Height → `height`; Design pressure → `pressure`; Flange rating → `rating`; Inlet size → `inletNps`; Outlet size → `outletNps`; Sand dump size → `sandNps`; Tag number → `tag` |
| `bullet-tank` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/bullet-tank.svg) | Horizontal capsule with hemispherical or 2:1 heads standing on two saddles, liquid inlet and vapour balance on top and liquid outlet at the bottom; a deluge ring or water-spray line is often drawn around it. *A horizontal capsule with no internals or boot in LPG / NGL storage service is a bullet; separators show a weir, boot or mesh pad. Spheres are circles on legs.* | V, T, TK | Pressure storage datasheet (ASME VIII-1 / API 2510 / NFPA 58): Head type → `heads`; Diameter → `diameter`; Length T/T → `length`; Design pressure → `pressure`; Flange rating → `rating`; Inlet nozzle size → `inletNps`; Outlet nozzle size → `outletNps`; Vapour nozzle size → `vapourNps`; Deluge ring → `deluge`; Tag number → `tag` |
| `slug-catcher` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/slug-catcher.svg) | An inlet header splitting into several parallel, slightly sloped long pipes (fingers), with gas risers from the top of the fingers to a gas header and the liquid draining to a liquid header at the low end. *Parallel sloped fingers between headers identify a finger slug catcher; a vessel-type slug catcher is drawn as a large horizontal separator.* | V, LT, PT | Slug catcher datasheet (ASME B31.8): Number of fingers → `fingers`; Finger size → `fingerNps`; Finger length → `length`; Slope → `slope`; Flange rating → `rating`; Inlet size → `inletNps`; Gas outlet size → `gasNps`; Liquid outlet size → `liquidNps`; Tag number → `tag` |
| `christmas-tree` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/christmas-tree.svg) | A vertical run of valves above the wellhead: lower master (manual), upper master (SSV, with an actuator box), a cross with the production wing valve (often actuated) and the choke (bow-tie with a diagonal arrow) on the side, and the swab valve and tree cap on top. The SCSSV is shown below the wellhead as a valve with a control-line note. *A single vertical valve stack with a side wing and choke is a tree; a stack of boxes with rams is a BOP; a stack of spools with only annulus outlets is the wellhead housing. Injector trees have the wing on the injection line with the flow arrow into the well. ISA codes here: XV = wing.* | XT, W, WH, SSV, USV, SCSSV, XV, PT, TT | Wellhead and christmas tree datasheet (API 6A: PSL, PR, temperature and material class): Rated working pressure → `pressureRating`; Tree bore → `bore`; Well type → `wellType`; Flowline size → `flowlineNps`; Flowline flange rating → `flowlineRating`; Tag number → `tag` |
| `choke-valve` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/choke-valve.svg) | An angle-body valve (side inlet, bottom outlet) or an in-line bow-tie with a diagonal arrow through it meaning adjustable restriction; a fixed (positive) choke has no arrow and a bean size note. Tagged HCV, PCV, FCV or CK. *The diagonal arrow = variable choke. An angle body with a spring is a PSV, not a choke. A globe control valve with a dome actuator can also do choking duty; then it is control-valve.* | CK, HCV, FCV, PCV, HCV, HV, FV, PV | Choke valve datasheet (API 6A): Inlet bore → `bore`; Outlet bore → `outletBore`; Rated working pressure → `pressureRating`; Operator → `operator`; Tag number → `tag` |
| `production-manifold` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/production-manifold.svg) | Two (or three) parallel headers, production and test, with each well flowline arriving through a check valve and branching to every header through its own valve, so one well can be routed to test while the rest go to production. *The repeating slot pattern (one inlet, one valve per header) is the signature. A single header with branches is just a header pipe. Test header size is usually smaller; HP / LP headers may both be present.* | M, MF | Manifold datasheet (ASME B31.3, API 6D valves): Number of well slots → `slots`; Slot pitch → `pitch`; Production header size → `productionNps`; Test header size → `testNps`; Inlet size → `inletNps`; Flange rating → `rating`; Tag number → `tag` |
| `pig-launcher` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/pig-launcher.svg) | An oversized barrel with a quick-opening closure (thick bar) at one end, a reducer to the pipeline size, the trap (isolation) valve on the pipeline, and a kicker (or bypass) line from the barrel round the trap valve; a pig signaller (XI / ZS) on the line. Receivers are drawn the same way, mirrored. *The closure plus reducer plus kicker line is unmistakable. A plain horizontal capsule is a vessel. Launcher or receiver is decided by flow direction.* | L, PL, SCR, XI, ZS, PI | Pig trap datasheet (ASME VIII-1 / ASME B31.4 / B31.8): Service → `service`; Pipeline size → `nps`; Flange rating → `rating`; Barrel length → `length`; Centreline elevation → `elevation`; Kicker size → `kickerNps`; Tag number → `tag` |
| `bop-stack` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/bop-stack.svg) | A vertical stack of boxes: the annular preventer on top (tapered or rounded), ram preventers (rectangles with rams drawn from both sides, labelled pipe / blind / shear), and a drilling spool with the choke and kill lines and their valves leaving each side. *Rams drawn as boxes with side rams distinguish a BOP from a christmas tree (bow-tie valves). Only on drilling or well-control schematics, not process P&IDs.* | BOP | BOP stack datasheet (API 16A / API 53): Bore → `bore`; Rated working pressure → `pressureRating`; Handling frame → `handlingFrame`; Tag number → `tag` |
| `riser` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/riser.svg) | The topsides line turning down through the deck to sea level and below, with the riser ESDV (actuated valve with an S box) above the deck, an insulating joint (two close bars with a gap) and an off-page note "to / from subsea pipeline"; the sea level is often drawn as a wave line. *An open-ended pipe hanging into the sea (pump or sump) is a caisson. Pipeline pig traps sit just upstream on the topsides.* | ESDV, PT, TT | Riser design basis / line list (API RP 2RD, ISO 13623): Riser size → `nps`; Flange rating → `rating`; Length below deck → `length`; Air gap → `airGap`; Topsides ESDV → `esdv`; Insulating joint → `insulatingJoint`; Tag number → `tag` |
| `wellhead-control-panel` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/wellhead-control-panel.svg) | A rectangle (local panel) labelled WHCP with hydraulic signal lines (marked with L) running to each well's SCSSV, SSV and wing valve actuators, and an ESD / fusible-loop input. *One hydraulic line per actuator per well. A box with only one hydraulic supply line is an HPU (hydraulic power unit), not the WHCP.* | X, WHCP | Wellhead control panel datasheet (API RP 14C / ISO 10418): Number of wells → `wells`; Number of accumulators → `accumulators`; Tag number → `tag` |
| `drilling-derrick` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/drilling-derrick.svg) | Elevation: a tall tapering lattice tower on a box substructure with the drill floor line between them and the crown block on top; in plan, the rig footprint rectangle with the well centre(s) marked as circles and slot numbers. *Never on process P&IDs except as a tie-in box (mud, cement, utilities). The BOP and wellhead below the floor are separate items.* | DR, RIG | Drilling structure datasheet (API 4F): Derrick height → `height`; Drill floor size → `floorSize`; Drill floor height → `floorHeight`; Tag number → `tag` |
| `wellhead-housing` [symbol](https://deck-twin-library.demoareeb.workers.dev/symbols/wellhead-housing.svg) | A stack of rectangles (casing head at the bottom, casing and tubing head spools above) on the conductor, each with side annulus outlets carrying gate valves and gauges; a blind flange or tree adapter on top. *Only annulus side outlets and no wing / choke means a wellhead without a tree (suspended well, or below a BOP). With a valve stack and choke on top it is a christmas-tree. ISA codes here: PI = annulus; PT = annulus.* | WH, W, PI, PT | Wellhead datasheet (API 6A): Rated working pressure → `pressureRating`; Top connection → `top`; Tag number → `tag` |