Smoke detector

Offshore F&G layout practice (ISA 5.1-style letter codes) / ISO 7240 / NFPA 72

Drawn as

A detector bubble with "SD".

Meaning

Point smoke detector (optical or ionisation) in control rooms, LERs, E-houses and quarters. Becomes smoke-detector. Beam detectors (beam-smoke-detector) and aspirating systems (aspirating-smoke-detector) are separate components.

Variants

Aspirating (VESDA) systems are a box "ASD" with a sampling pipe with holes
Beam smoke detectors are drawn as a Tx/reflector pair
In-duct smoke detectors are drawn on the HVAC duct