Deluge Valve series CA-FIRE

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 in the heat of the fire above them. 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. The correct choice depends entirely on the system type, which is determined by the hazard and its rate of fire spread.

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 (no components in the flow stream) with head loss below 0.08 MPa. It is suitable for working pressures up to 1.6 MPa. The diaphragm is straightforward to replace during maintenance without removing the valve body from the pipeline. The diaphragm type is the correct choice for the majority of standard industrial and commercial applications where supply pressure is at or below 1.6 MPa.

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 in high-pressure supply systems. The piston mechanism is less susceptible to deformation under repeated pressure cycling than a rubber diaphragm. 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 where the piston must hold against the combined effect of the supply pressure and the downstream supervisory air charge.

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 during normal operation or during a fault condition. 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 in the valve station — 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) and Ex tb IIIC T80°C Db for combustible dust atmospheres. 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 and prevent propagation to the surrounding atmosphere.

Typical applications requiring Ex-rated deluge valves include: petrochemical process units, refinery pump rooms, LPG/LNG storage facilities, offshore platform process decks, paint spray facilities, solvent storage areas, coal handling and dust-generating processes, and any location that appears on the hazardous area classification drawing with a Zone 1 or Zone 2 boundary. If you have an area classification drawing, CA-FIRE can confirm the appropriate Ex variant for your specific zone.

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 vents the control chamber and opens the deluge valve in under 1 second. This is the simplest, fastest, and most reliable option where a dependable electrical supply is available. It also allows the easiest integration with building management systems, remote monitoring, and multi-zone control panels. Specify solenoid actuation for the vast majority of industrial and commercial applications.

Wet pilot actuation uses a pressurised water pilot line from a separate detector valve (typically a rate-of-rise or fixed-temperature pilot sprinkler on a closed system) 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. Used in remote locations where power reliability is uncertain, in some outdoor or buried valve installations, and in systems where the authority having jurisdiction specifies hydraulic actuation.

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 and pipe failure. 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. For most standard indoor applications, specify electric solenoid. For freezing or remote outdoor environments, specify dry pilot. Specify wet pilot where hydraulic independence from electrical power is a specific design requirement.

CA-FIRE's deluge valve skids and horizontal assemblies are fully integrated factory-built stations. A standard assembly includes: the deluge alarm valve body (the primary control valve), upstream supply isolation valve (OS&Y gate valve or butterfly valve), downstream system isolation (where specified), solenoid trip valve (Ex-rated on hazardous area models), wet-pilot and dry-pilot trim connections, priming line ball valve, main drain valve, test and drain manifold with ball valves, supply pressure gauge, system pressure gauge, pilot pressure gauge, alarm pressure switch (Ex-rated on hazardous area models), water motor alarm gong with strainer, supervisory low-pressure switch (on pre-action variants), interconnecting carbon steel pipework (SS304/316 on stainless variants), structural steel skid frame with mounting feet, and local explosion-proof control panel with terminal strip for field wiring connections.

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 to the incoming main, the system flange connection to the downstream nozzle pipework, and the electrical cable entry to the local panel terminal strip. The typical site connection time for an experienced contractor is two to four hours, compared to several days for a site-assembled valve station from loose components.

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 (mill certs on pressure-retaining components), 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. To receive a quotation, please provide: system design flow rate and pressure at the valve inlet, required nominal size(s), number of valve stations, hazardous area classification (if applicable), material preferences, connection standard (GB or ANSI flanges), actuation mode preference, and any specific Ex certification requirements. Contact sales@ca-fire.com or WhatsApp +86 18150362095 with your project details.