Preaction sprinkler system
Preaction adds detection and release logic to a sprinkler system; single- and double-interlock arrangements are not interchangeable.
How it works
Control water admission to system piping through a defined detection and valve-release sequence before sprinkler discharge conditions are met.
Where it fits
Expert-reviewed applications where accidental water exposure and fire response are balanced under adopted requirements.
Where it breaks
The release sequence, detection zones, supervision, delivery time, manual actions or impairment states are not documented.
Tradeoff register
- Adds a supervised release layer
- More dependencies than wet pipe
- Cause/effect and testing become central
Interactive teaching model
This card connects to the fire lab. Its output is a bounded calculation or an illustrative directional model, not measured site data or a commissioned design result.
Source register
These sources support the teaching summary. Use current standards, site engineering and authority approval for real work.
- NFPA 13 (2025) — Installation of Sprinkler Systems
NFPA · NFPA LiNK access conditions apply · reviewed 2026-08-26. Rights note: Link to the official edition; do not reproduce system requirements or substitute for adopted code. - NFPA 75 (2024) — Fire Protection of Information Technology Equipment
NFPA · NFPA LiNK access conditions apply · reviewed 2026-08-26. Rights note: Link to the official edition; do not reproduce or paraphrase requirements as local approval.