Industrial Fire Sprinkler

The standard 74°C (yellow bulb) activation temperature for CHSAZ 202/242 and CHSAX 202/242 reflects the higher ambient temperature that large industrial facilities — factories, production halls, process plants — routinely experience in normal operation. The 30°C safety margin rule (activation temperature must be at least 30°C above maximum normal ambient) means that factory spaces with peak ambient temperatures up to 44°C require 74°C heads. Using 68°C heads in a factory with summer ambient of 42–44°C risks false activation from ambient heat alone.

For civil occupancies with controlled ambient temperatures (air-conditioned exhibition halls, sports arenas, airport terminals) where the ambient rarely exceeds 38°C, the CHSAK-Z and CHSAK-X quick response models with 68°C activation temperature are appropriate and preferable for their faster life-safety response.

Yes — the CHSA series is compatible with dry-pipe and pre-action systems, making it suitable for industrial facilities that include unheated spaces or areas with seasonal freeze risk. This is a practical advantage in northern China and cold-climate industrial projects where wet-pipe cannot be used in unheated sections of a large factory complex.

However, note that GB 50084 and NFPA 13 have specific provisions on dry-pipe system response time for large K-factor heads — the greater water volume required to fill the pipe before discharge makes the response time penalty of a dry-pipe system more significant for large-K heads than for standard K5.6 heads. Wherever possible, wet-pipe is preferred for CHSA applications. Use dry-pipe only where freeze protection genuinely requires it.

According to GB 50084 and the CA-FIRE product listing, all CHSA K-factor models (K11.3 through K25.2) are listed for use in spaces with a maximum ceiling height of 18 m for civil buildings and 12 m for factory buildings. The table below summarises the key ceiling height boundaries:

• Factory / industrial occupancies: 8–12 m ceiling — all K-factor models applicable; select K-factor based on hazard class and required application rate
• Civil / public buildings: 8–18 m ceiling — K14.2, K17.0, and K25.2 models cover the full range; K11.3 may be used up to approximately 12 m in lighter civil applications

Note that the minimum ceiling height of 8 m is a firm lower bound — using CHSA heads in spaces below 8 m is not listed and may not comply with the relevant code. Standard K5.6 or K8.0 heads are the correct specification for ceiling heights below 8 m in ordinary and extra hazard occupancies.

This is a critical design question. CHSA non-warehouse heads are not listed for storage applications regardless of ceiling height. If the building contains high-piled storage on racks with goods stacked above 3.5 m, the occupancy is reclassified as a storage hazard under GB 50084 (and NFPA 13 Section 12) — and the applicable heads are CMSA or ESFR, not CHSA.

If the building is primarily a factory or civil occupancy with a small area of incidental storage (flat-stacked goods, process materials) that does not constitute high-piled storage as defined by GB 50084, CHSA heads may remain appropriate for the non-storage portions of the building. The specific storage arrangement must be reviewed by the system designer and authority having jurisdiction before confirming that CHSA heads are acceptable.

The hydraulic performance — K-factor, minimum pressure, flow rate — is identical between CHSAZ (upright) and CHSAX (pendent) for the same K-factor. The difference is purely the orientation and spray pattern direction:

CHSAZ (upright): Mounted with the deflector above the pipe; water sprays upward and outward from the deflector. Used on exposed pipe systems below open structural roofs in factory buildings. The upright position protects the deflector from accumulation of dust and debris from above, which is important in production environments.

CHSAX (pendent): Mounted with the deflector below the pipe; water sprays downward and outward. Used below finished suspended ceilings in civil buildings — convention centres, airports, sports halls. Provides a neater installation when the pipe is concealed above a suspended ceiling tile grid.

In buildings with exposed steel roof structures (common in industrial facilities), upright heads (CHSAZ) are typically preferred because they can be located at the roofline without requiring a dropped ceiling. In buildings with finished ceilings, pendent (CHSAX) is the standard choice.