Deluge Valve

A deluge valve is the master control valve in an open-head fire suppression system. The downstream pipework contains no water in standby — all open nozzles are permanently exposed to the atmosphere. Water is held back solely by the closed deluge valve. When a fire signal trips the valve, water floods the entire zone simultaneously from every nozzle. This simultaneous full-zone discharge is the defining characteristic of a deluge system.

An alarm check valve (wet alarm valve) serves a completely different system type — a closed-head wet-pipe sprinkler system where the downstream pipework is filled with pressurised water at all times and individual sprinkler heads open one at a time when their fusible element melts. The alarm check valve detects flow and trips the alarm, but it does not control activation — the sprinkler heads themselves control when and where water discharges.

The two valve types are never interchangeable. If your system has permanently open nozzles (deluge, water spray, or foam-water), specify a deluge valve. If it has closed fusible-element sprinkler heads, specify an alarm check valve.

Both types use fluid pressure in a control chamber to hold the valve closed during standby. The difference is in the sealing element and the resulting pressure rating and performance characteristics.

A diaphragm deluge valve uses a flexible EPDM rubber diaphragm as both the sealing element and the actuating mechanism. The diaphragm provides a full-bore, unobstructed flow path with head loss below 0.08 MPa. It is suitable for working pressures up to 1.6 MPa. The diaphragm type is the correct choice for the majority of standard industrial and commercial applications.

A piston-type deluge valve uses a machined piston in a cylinder bore as the sealing element. The piston design can withstand significantly higher working pressures — CA-FIRE's piston-type models are rated to 2.5 MPa — and provides superior resistance to pressure transients and water hammer. Piston-type valves are the correct choice when supply pressure exceeds 1.6 MPa, in high-pressure petrochemical supply systems, and in the pre-action configuration.

An explosion-proof deluge valve is required wherever the valve station is located in a classified hazardous area — a location where flammable gases, vapours, or combustible dust are present at concentrations that could be ignited by an electrical spark. Standard deluge valves use electrical components (solenoid valves, pressure switches, water motor gong motors) that can produce sparks. In a Zone 1 or Zone 2 atmosphere, a single spark is sufficient to ignite the surrounding atmosphere.

The Ex certification covers all electrical components — not just the solenoid. CA-FIRE's ZSFM-Ex series carries Ex db IIC T6 Gb certification (IIC is the most demanding gas group, covering hydrogen and acetylene). Every electrical component — solenoid trip valve, pressure switches, water motor gong, junction boxes, local control panel — is enclosed in certified flameproof housings designed to contain any internal ignition source.

Typical applications requiring Ex-rated deluge valves include: petrochemical process units, refinery pump rooms, LPG/LNG storage, offshore platform process decks, paint spray facilities, solvent storage areas, coal handling, and any location that appears on the hazardous area classification drawing with a Zone 1 or Zone 2 boundary.

Electric solenoid actuation (the most common) connects the deluge valve directly to the fire detection and alarm panel. When a detector activates, the control panel energises the solenoid trip valve, which opens the deluge valve in under 1 second. This is the simplest, fastest, and most reliable option where a dependable electrical supply is available.

Wet pilot actuation uses a pressurised water pilot line from a separate detector valve to trip the deluge valve hydraulically — no electrical power is required for the activation event. This provides full independence from the electrical supply and eliminates the risk of solenoid failure as a single point of failure.

Dry pilot actuation replaces the water pilot line with a pressurised air or nitrogen pilot line. The dry pilot is the correct choice in freezing environments where a water pilot line would be at risk of ice formation. It is also used in CA-FIRE's stainless steel Ex valve for pure pneumatic control installations where no electrical power is available at the valve location.

CA-FIRE's deluge valve skids and horizontal assemblies are fully integrated factory-built stations. A standard assembly includes: the deluge alarm valve body, upstream supply isolation valve, downstream isolation (where specified), solenoid trip valve (Ex-rated on hazardous area models), wet-pilot and dry-pilot trim connections, main drain valve, test and drain manifold, supply pressure gauge, system pressure gauge, pilot pressure gauge, alarm pressure switch, water motor alarm gong with strainer, interconnecting pipework, structural steel skid frame, and local explosion-proof control panel with terminal strip.

At the factory, every assembly is subjected to a full hydraulic pressure test at 1.5× working pressure, a functional test of the solenoid trip sequence, verification of the alarm gong and pressure switch activation points, and a reset verification. A factory test report is provided with every shipment. On site, the installation team makes three connections: the supply flange connection, the system flange connection, and the electrical cable entry. Typical site connection time is two to four hours, compared to several days for a site-assembled valve station.

CA-FIRE specialises in the fire suppression hardware — deluge valves, valve skids and assemblies, fire monitors, foam bladder tanks, alarm check valves, gate valves, hydrants, and fire sprinkler heads — and can supply all of these components from a single source for a complete deluge system. For projects requiring a full system package, CA-FIRE can also coordinate supply of spray nozzles, foam-water monitor nozzles, and system trim components.

For BRI export projects and international EPC contracts, CA-FIRE provides full English-language technical documentation packages including: product datasheets with GB, NFPA, and CE/Ex certification references, material certificates, hydrostatic test reports, factory inspection reports, packing lists, and installation and maintenance manuals. Third-party inspection by SGS, BV, or similar inspection agencies can be arranged for witnessed factory acceptance testing. Contact sales@ca-fire.com or WhatsApp +86 18150362095 with your project details.