Blowdown valve (BDV)

Depressuring valve: full-bore trunnion ball valve with a red spring-return scotch-yoke actuator that fails open, normally closed. Same accessories as the ESDV: limit switch box, solenoid, quick exhaust, filter-regulator and tubing. open turns the ball and the indicator.

Installation

Copies valves/blowdown-valve.tsx and the shared lib/ into src/components/deck-twin/. Needs three, @react-three/fiber and @react-three/drei. See installation for the manual route.

Usage

import { Canvas } from '@react-three/fiber'
import { OrbitControls } from '@react-three/drei'
import { Stage } from './components/deck-twin/lib/stage'
import { BlowdownValve } from './components/deck-twin/valves/blowdown-valve'

export default function Scene() {
  return (
    <Canvas shadows camera={{ position: [8, 5, 9], fov: 35 }}>
      <Stage>
        <BlowdownValve />
      </Stage>
      <OrbitControls makeDefault />
    </Canvas>
  )
}

Props

P&ID

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).

tag BDVISA BDVISA XVISA ZSOISA ZSCISA 5.1 (actuator) on an ISO 10628-2 ball valve body; API 521 depressuring

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.

Blowdown valve datasheet (API 6D + actuator sheet, API 521 depressuring case) fields and the props they set

Sizenps

Pressure classrating

Tag numbertag

Typical suppliers

Emerson Bettis · Cameron (SLB). The geometry is generic and sized from public standards. It is not vendor CAD.

For agents

Machine-readable entry with props, ranges, defaults and ports:

Or fetch /r/blowdown-valve.json, or copy a ready-made instruction:

Add the Deck Twin "Blowdown valve (BDV)" component to this project. Run `npx -y https://decktwin.com/cli/deck-twin-0.2.2.tgz add blowdown-valve` (it copies the file and the shared lib into src/components/deck-twin/), then `npx -y https://decktwin.com/cli/deck-twin-0.2.2.tgz info blowdown-valve` for its props, ranges and ports. Render <BlowdownValve /> inside a React Three Fiber <Canvas shadows>, wrapped in <Stage> from src/components/deck-twin/lib/stage. Set props from my data (metres, NPS in inches, ASME class) and leave the rest at defaults. Install three, @react-three/fiber, @react-three/drei and @types/three if they're missing. Full guide: https://decktwin.com/skill/SKILL.md