Explosion Proof Deluge Valve — 2.5 MPa, DN50–DN300, Ex db IIC T6 Gb
✓ 2.5 MPa Working Pressure✓ Ex db IIC T6 Gb / Ex tb IIIC T80°C Db✓ Zone 1 / Zone 2 · Zone 21 / Zone 22✓ IP65✓ Piston-Type Mechanism✓ DN50–DN300 · 9 Sizes✓ Auto · Remote · Manual — Triple Redundancy✓ -20°C to +70°C✓ GB 5135.7 · NFPA 13/15 · IEC 60079 · ISO 9001
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CA-FIRE's explosion proof deluge valve (Model ZSFM 50~300-2.5-Ex) is a purpose-engineered piston-type fire suppression control valve for classified hazardous areas — combining 2.5 MPa high-pressure performance, full Ex db IIC T6 Gb / Ex tb IIIC T80°C Db certification across all electrical accessories, and triple-redundant activation (automatic detection, remote panel linkage, on-site manual release). Every electrical component in the valve station — solenoid, pressure switches, alarm gong, junction boxes, and local control panel — is housed in certified flameproof enclosures rated IP65. Available in nine sizes from DN50 to DN300 for flanged connection. The 2.5 MPa rating — 56% above the 1.6 MPa standard range — makes this the correct specification for petrochemical refineries, LNG terminals, oil and gas processing plants, coal handling facilities, and chemical warehouses where both hazardous area classification and elevated supply pressure apply simultaneously. For the complete deluge valve range, see the CA-FIRE series overview.
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Explosion-Proof Certification — Zone Coverage & What It Means
The Ex db IIC T6 Gb / Ex tb IIIC T80°C Db certification on this explosion proof deluge valve covers every electrical component in the valve station — solenoid trip valve, alarm pressure switch, water motor gong motor, junction boxes, and local control panel. Each component is enclosed in a certified flameproof housing designed to contain any internal ignition event and prevent propagation to the surrounding atmosphere. This is not an add-on feature — it is fundamental to the valve's design and the component selection process.
| Zone | Classification | Typical Installation Location | This Valve Certified |
|---|---|---|---|
| Zone 1 | Explosive gas/vapour — likely present under normal operation | Pump rooms, valve pits, compressor areas, loading gantries, process vessels | ✓ Ex db IIC T6 Gb |
| Zone 2 | Explosive gas/vapour — unlikely under normal operation | Tank farm perimeters, storage buildings, outdoor process areas, equipment rooms | ✓ Ex db IIC T6 Gb |
| Zone 21 | Explosive dust cloud — likely present under normal operation | Coal handling, grain silos, chemical powder processing, spray drying | ✓ Ex tb IIIC T80°C Db |
| Zone 22 | Explosive dust cloud — unlikely under normal operation | Peripheral areas of coal prep plants, flour mills, wood processing facilities | ✓ Ex tb IIIC T80°C Db |
IIC gas group explained: Gas Group IIC is the most demanding explosion-proof classification, covering hydrogen (H₂) and acetylene (C₂H₂) — the most easily ignited industrial gases. A valve certified to IIC is automatically suitable for all lower gas groups (IIB, IIA). T6 temperature class means all accessible external surfaces of the flameproof housings remain below 85°C under the highest anticipated fault conditions — preventing auto-ignition of surrounding substances with ignition temperatures as low as 85°C. IP65 means the enclosures are completely dust-tight and resistant to direct water jets from any angle — suitable for outdoor installation and hose-down cleaning environments.
Explosion Proof Deluge Valve — Dimensional Data
| DN (mm) | Height (mm) | Flange Bolt Circle (mm) | No. of Bolts | Weight (kg) |
|---|---|---|---|---|
| DN50 | 270 | 160 | 8 | 45 |
| DN65 | 270 | 180 | 8 | 58 |
| DN80 | 320 | 200 | 8 | 72 |
| DN100 | 320 | 220 | 8 | 95 |
| DN125 | 365 | 250 | 8 | 130 |
| DN150 | 365 | 280 | 8 | 165 |
| DN200 | 480 | 340 | 12 | 240 |
| DN250 | 610 | 400 | 12 | 320 |
| DN300 | 690 | 460 | 16 | 450 |
* Flange standard: GB as standard · ANSI B16.5 available on request · Dimensional drawings (PDF + DWG) provided free on request — sales@ca-fire.com
Key Features of the Explosion Proof Deluge Valve
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🔴 2.5 MPa High-Pressure Piston Mechanism The 2.5 MPa working pressure — 56% above the 1.6 MPa standard for diaphragm deluge valves — is not merely a pressure uprating of an existing design. The ZSFM-Ex uses a machined piston mechanism rather than a flexible diaphragm, selected specifically for high-pressure duty because the piston geometry provides inherently higher resistance to water hammer and pressure transients than a rubber diaphragm. In petrochemical supply systems where pump start/stop events can generate brief pressure spikes, the piston mechanism absorbs these events without risk of diaphragm deformation or premature seat leakage. The strength test pressure of 10.0 MPa (4× working pressure) confirms the structural margin engineered into every valve body. Maximum flow rate reaches 400 L/s (DN-dependent), enabling a single valve to supply large-area deluge zones simultaneously at design discharge density without pressure drop at the nozzle. Downstream hydraulic resistance is held below 0.08 MPa across the full rated flow range. |
⚡ Full-Station Explosion-Proof Design — No Exceptions Standard explosion-proof valves sometimes use Ex-rated solenoids but standard pressure switches or terminal boxes. The ZSFM-Ex applies Ex certification to every electrical component in the station without exception: the solenoid trip valve (DC24V, 12W), alarm pressure switch, water motor gong motor, all junction boxes and cable glands, and the local explosion-proof control panel (DC24V, 55W). All housings meet Ex db IIC T6 Gb (flameproof enclosure, gas group IIC, temperature class T6, Equipment Protection Level Gb) and Ex tb IIIC T80°C Db (dust enclosure, dust group IIIC, max surface temperature 80°C). IP65 enclosure rating provides complete dust exclusion and protection against water jets — essential for outdoor LNG terminal and refinery pipe-rack installations subject to wash-down and rain. No single component in the station can initiate an ignition event in the surrounding hazardous atmosphere. |
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🔁 Triple Activation Redundancy — Auto · Remote · Manual Automatic activation: Explosion-proof heat or smoke detectors send a signal to the local Ex-rated control panel, which energises the solenoid trip valve and vents control-chamber pressure. The piston lifts fully open within ≤ 2 seconds of signal receipt. This is the primary activation path in all automated systems. Remote linkage: The local control panel integrates with the facility's central fire alarm system (FAS) or distributed control system (DCS) via hardwired or fieldbus connection — enabling zone-by-zone activation from the main control room. Essential for large petrochemical complexes where a single FAS manages dozens of deluge valve zones across multiple process units. Manual on-site release: An explosion-proof manual release button at the valve station bypasses both the detector and panel circuits — activating the system directly in ≤ 1 second from an operator's hand. This provides the final backup path that operates regardless of detector status, panel power, or communication faults. |
🏗️ Factory-Tested Complete Station — Skid Option Available The explosion proof deluge valve is available as a standalone valve body with trim, or as a complete factory-assembled skid station — see the Deluge Valve Skid (Vertical) and Horizontal Deluge Valve Assembly for the skid-mounted versions. Every standalone valve undergoes factory testing before shipment: ✓ Hydrostatic strength test at 10.0 MPa Factory test report, material certificate, and Ex certification documentation are provided with every unit. Third-party inspection by SGS, BV, or equivalent agencies can be arranged for witnessed factory acceptance testing on project orders. |
Explosion Proof Deluge Valve — Working Principle
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① Standby Condition The piston is held in the closed position by pressurised water in the control chamber, acting against the supply pressure. At 2.5 MPa supply, the control-chamber geometry is engineered to provide a net closing force significantly greater than the opening force from supply pressure — ensuring positive closure with zero leakage ≤ 0.1 L/min even at maximum rated working pressure. All downstream open-nozzle pipework remains dry at atmospheric pressure. The Ex-rated detector loop and control panel monitor the protected zone continuously. Pressure gauges (supply and pilot) confirm system integrity at a glance. |
② Fire Detection → Solenoid Trip An Ex-rated heat or smoke detector identifies a fire condition and sends a signal to the local explosion-proof control panel. The panel energises the Ex-rated solenoid trip valve (DC24V, 12W) on the control chamber vent line. The solenoid opens and vents control-chamber pressure to drain within 1 second of signal receipt. Simultaneously, the event is logged at the local panel and transmitted to the central FAS/DCS via the panel's output contacts. Remote activation from the control room, or manual activation using the on-site Ex-rated push button, produce the same result via different input paths. |
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③ Piston Opens — High-Pressure Zone Discharge With control pressure removed, 2.5 MPa supply pressure acts on the base of the piston and drives it fully open within ≤ 2 seconds. The complete bore is exposed — hydraulic resistance drops to below 0.08 MPa. Water (or foam-water mixture from the upstream proportioner) floods the downstream distribution pipework at design flow rate — up to 400 L/s depending on DN size — and discharges simultaneously from every open nozzle across the entire protected zone. In a high-pressure supply system, the downstream pipework fills and achieves design discharge pressure measurably faster than at 1.6 MPa — a critical performance advantage for fast-developing petrochemical fires. |
④ Alarm · Reset · Restoration Flow through the alarm port drives the Ex-rated water motor alarm gong and closes the Ex-rated alarm pressure switch — sending an electrical signal to the fire alarm panel and monitoring system. To reset after suppression: (1) isolate upstream supply; (2) de-energise solenoid; (3) drain downstream via main drain; (4) re-pressurise control chamber; (5) confirm piston has reseated — zero flow at drain; (6) restore detector and solenoid circuit; (7) open upstream supply to standby. Full restoration by one qualified technician: 20–40 minutes. No special tools required beyond standard flanged valve toolkit. Post-suppression inspection of the piston seal and seat is recommended before returning to standby. |
Applications — Where the Explosion Proof Deluge Valve Is Specified
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Petrochemical Refineries Distillation towers, catalytic cracking units, reactor vessels, and solvent storage areas are Zone 1/2 classified by design. Supply pressure in large refineries commonly exceeds 1.6 MPa to maintain adequate flow at elevated process unit platforms — making the 2.5 MPa ZSFM-Ex the only correct valve specification for these locations. IIC gas group covers all hydrocarbon vapours and hydrogen-containing streams. Zone 1/2 · 2.5 MPa · IIC gas group |
LNG Terminals & Gas Processing LNG liquefaction trains, regasification units, and onshore gas processing plants handling methane and hydrogen sulphide — all classified Zone 1 or Zone 2. Cryogenic temperatures at the process side are handled by the carbon steel valve body rated to -20°C. The 2.5 MPa rating accommodates the high supply pressures required by elevated pipe rack installations in large LNG terminal layouts. Zone 1/2 · -20°C · LNG/H₂S service |
Coal Handling & Preparation Plants Coal transfer points, crusher houses, screen buildings, and belt conveyor galleries generate Zone 21/22 combustible coal dust atmospheres. The Ex tb IIIC T80°C Db dust certification covers all coal dust applications. Total-zone deluge suppression prevents coal dust deflagration from developing into a full detonation — required by coal mine safety regulations in China and internationally. Zone 21/22 · Ex tb IIIC dust · Coal dust |
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Chemical Warehouses & Tank Farms Bulk storage of flammable solvents, adhesives, paints, and chemical feedstocks in Zone 2 areas. The 2.5 MPa ZSFM-Ex supplies high-flow deluge at the density required for large flammable liquid storage warehouses — compatible with foam-water mixture at 6% for direct foam-water deluge suppression of solvent pool fires without system modification. Zone 2 · Foam-water 6% · High flow |
Power Generation — Oil-Insulated Transformers Outdoor oil-insulated power transformers are classified Zone 2 due to transformer oil vapour. Deluge protection of transformer bays at power stations and substations. The Ex-rated accessories on the ZSFM-Ex valve station comply with the Zone 2 classification at the transformer, while the 2.5 MPa pressure accommodates elevated supply systems at large power station pump stations. Zone 2 · Transformer oil · Power station |
BRI Export — EPC Petrochemical Projects Chinese EPC contractors building refineries, LNG terminals, and petrochemical complexes in Southeast Asia, Middle East, Central Asia, and Africa specify GB or NFPA fire protection equipment with IECEx-equivalent Ex certification. CA-FIRE supplies the ZSFM-Ex to BRI export projects with full English-language GB 5135.7 certification, IEC 60079 Ex documentation, NFPA hydraulic data (Cv per DN), and ANSI flanges on request. IECEx · NFPA · ANSI flanges · English docs |
Explosion Proof Deluge Valve vs Standard Deluge Valve — Key Differences
| Parameter | Explosion-Proof Deluge Valve ZSFM-Ex (This Product) |
Standard Diaphragm Valve ZSFM 1.6 MPa |
Stainless Steel Ex Valve ZSFM-P-Ex |
|---|---|---|---|
| Working pressure | 2.5 MPa | 1.6 MPa | 1.6 MPa |
| Mechanism | Piston-type | EPDM diaphragm | EPDM diaphragm |
| Ex certification | ✓ Ex db IIC T6 Gb | No | ✓ Ex db IIC T6 Gb |
| Body material | Carbon steel | Cast iron | SS304 / SS316 |
| Corrosion resistance | Standard (epoxy coating) | Standard | ✓ High — marine/offshore |
| Water hammer resistance | ✓ High — piston design | Standard | Standard |
| Pneumatic actuation option | No (electric solenoid) | ✓ Wet/dry pilot | ✓ Air-controlled (primary) |
| Operating temperature | -20°C to +70°C | 4°C to 70°C | -20°C to +70°C |
| Best application | Zone 1/2 + high pressure >1.6 MPa | Standard — non-hazardous area | Zone 1/2 + corrosive / offshore |
Applicable Standards & Certifications
| Standard | Scope & Relevance to This Product |
|---|---|
| GB 5135.7-2019 | 自动喷水灭火系统 第7部分 — National standard governing deluge valve performance, pressure testing, and certification. Primary certification standard for all ZSFM-Ex series valves. National fire product type approval held. |
| IEC 60079-0 / 60079-1 | Explosive atmospheres — General requirements (IEC 60079-0) and Flameproof enclosures (IEC 60079-1). The international standards underlying the Ex db IIC T6 Gb certification. All Ex-rated electrical accessories on the ZSFM-Ex comply with these standards. IECEx scheme certificates available for international project submissions. |
| IEC 60079-31 | Explosive atmospheres — Protection by enclosure "t" for dust. The standard underlying the Ex tb IIIC T80°C Db certification for Zone 21/22 combustible dust atmospheres. Covers coal dust, grain dust, and chemical powder environments. |
| NFPA 13 / NFPA 15 | Standard for Sprinkler Systems (NFPA 13) and Water Spray Fixed Systems (NFPA 15). CA-FIRE provides Cv values and hydraulic performance data per DN size for NFPA-based hydraulic calculations. ANSI B16.5 flange connections available on request for NFPA export projects. |
| NFPA 30 | Flammable and Combustible Liquids Code. Governs fire protection system design for flammable liquid storage — the primary NFPA design standard for tank farm and warehouse deluge systems where the ZSFM-Ex is specified. |
| GB 50151 | 泡沫灭火系统设计规范 — Design standard for foam fire extinguishing systems. Applicable when the ZSFM-Ex is used as the control valve in a foam-water deluge system for flammable liquid protection. |
| ISO 9001:2015 | CA-FIRE quality management system certification — covers design, manufacturing, pressure testing, Ex component inspection, and shipment for all ZSFM-Ex products. |
Frequently Asked Questions — Explosion Proof Deluge Valve
What makes an explosion proof deluge valve different from a standard deluge valve?
A standard deluge valve uses electrical components — solenoid valves, pressure switches, and alarm gong motors — that are not designed to prevent their internal sparking or arcing from igniting a surrounding flammable atmosphere. In a Zone 1 or Zone 2 hazardous area, a single electrical spark can be sufficient to ignite the surrounding gas or vapour mixture.
An explosion proof deluge valve addresses this by enclosing every electrical component in certified flameproof (Ex d) housings. These housings are designed and tested to contain any internal ignition event — and to prevent flames or hot gases from escaping to the surrounding atmosphere — even under the most demanding internal explosion conditions. The IIC gas group certification means the housings meet the most demanding test conditions (hydrogen/acetylene), making the valve suitable for virtually all hazardous gas atmospheres encountered in industrial fire protection.
Crucially, this must apply to every electrical component in the valve station — not just the main solenoid. CA-FIRE's ZSFM-Ex applies Ex db IIC T6 Gb certification to all accessories: solenoid, pressure switches, water motor gong, junction boxes, cable glands, and local control panel. IP65 enclosure protection completes the station specification for outdoor installation.
When do I need a 2.5 MPa explosion proof deluge valve rather than a 1.6 MPa model?
Specify the 2.5 MPa explosion proof deluge valve when both of the following conditions apply: (1) the installation location is in a classified hazardous area (Zone 1, Zone 2, Zone 21, or Zone 22), AND (2) the available fire water supply pressure at the valve inlet is above 1.6 MPa, or the hydraulic design of the system requires an inlet pressure above 1.6 MPa to achieve the required discharge density at the nozzle.
High supply pressure commonly occurs in large petrochemical refineries and LNG terminals where the fire water ring main is pressurised above 1.6 MPa to maintain adequate residual pressure at elevated process unit platforms and long pipe-run nozzle arrays. Using a 1.6 MPa valve in these conditions would be operating outside the valve's pressure rating — a safety and compliance issue.
If the hazardous area classification applies but the supply pressure is at or below 1.6 MPa, the standard Ex-rated diaphragm variant may be appropriate — contact CA-FIRE with your supply pressure data and we will confirm the correct specification.
What does Ex db IIC T6 Gb mean — is this the same as ATEX?
Ex — the component is certified for use in explosive atmospheres. db — the protection method is "flameproof enclosure" (IEC terminology, same as "d" in older ATEX notation), meaning the enclosure is designed to contain any internal explosion and prevent propagation to the surroundings. IIC — gas group IIC, the most demanding classification, covering hydrogen (H₂) and acetylene (C₂H₂). A component certified to IIC is automatically suitable for all lower gas groups (IIB covers ethylene; IIA covers propane and most common hydrocarbons). T6 — temperature class T6, meaning the maximum external surface temperature under the most severe fault conditions does not exceed 85°C. Gb — Equipment Protection Level b for gas atmospheres, suitable for Zone 1 and Zone 2.
ATEX is the European Union directive (2014/34/EU) governing Ex-certified equipment sold in the EU. IECEx is the equivalent international certification scheme. The underlying technical standards (IEC 60079 series) are the same for both schemes — an Ex db IIC T6 Gb component meets the technical requirements of both ATEX and IECEx. CA-FIRE's ZSFM-Ex components are certified to the IEC 60079 standards; for ATEX-specific documentation for EU project submissions, contact sales@ca-fire.com.
Can this explosion proof deluge valve be used with foam suppression systems?
Yes. The ZSFM-Ex is fully compatible with foam-water mixture at concentrate ratios up to 6% — covering AFFF, AR-AFFF, FFFP, and protein foam concentrates. The valve body and internal wetted components are rated for continuous foam-water service at 2.5 MPa working pressure. This makes the ZSFM-Ex the correct specification for flammable liquid storage tank farm deluge systems, LNG loading gantry foam-water systems, and chemical warehouse foam-water deluge — all of which typically combine Zone 1/2 classification with foam-water suppression and frequently with high supply pressure.
The upstream foam proportioning equipment (balanced-pressure proportioner, bladder tank system, or inline inductor) is connected on the supply side of the deluge valve and delivers pre-mixed foam solution to the valve inlet. The valve itself is agnostic to whether it is handling water or foam-water mixture — it simply controls whether flow reaches the downstream nozzle network.
What is included in the explosion proof deluge valve station — is a skid option available?
The standard ZSFM-Ex valve is supplied as a valve body with complete explosion-proof trim: Ex-rated solenoid trip valve, Ex-rated alarm pressure switch, Ex-rated water motor alarm gong, control chamber priming line with ball valve, main drain valve, supply pressure gauge, system pressure gauge, pilot pressure gauge (where applicable), manual release button, and interconnecting trim pipework pre-assembled to the valve body. The local explosion-proof control panel (DC24V, 55W) with terminal strip for field wiring connections is supplied separately or as part of the skid assembly.
For projects requiring a complete factory-assembled and pressure-tested station, CA-FIRE supplies the ZSFM-Ex valve as the core component of a vertical explosion-proof deluge valve skid or horizontal deluge valve assembly. These skid products include all trim, upstream isolation valve, structural steel skid frame, and local Ex control panel — factory pressure-tested and ready for three site connections (supply flange-in, system discharge flange-out, electrical cable entry).
What maintenance is required — and what is the inspection schedule for hazardous area installations?
Quarterly: Visual inspection of valve body, trim piping, and all Ex-rated housings for mechanical damage or corrosion. Check pressure gauge readings confirm standby pressures are within specification. Inspect Ex component cable entries (cable glands) for integrity — damaged cable glands compromise the Ex certification of the enclosure. Check anti-corrosion coating on valve body for signs of damage and touch up as required.
Annually: Functional test of solenoid activation using the test drain valve — confirm valve opens and reseats correctly. Test the alarm gong and alarm pressure switch activation. Verify all three activation modes (auto, remote, manual) produce the expected response at the local control panel and remote FAS. Inspect Ex housing bolting — all flame path gap bolts must be present and at specified torque.
Biennially (every 2 years): Disassemble and inspect piston seal and seat; replace piston seal if wear, deformation, or chemical degradation is observed. Inspect valve seat for scoring. Full inspection of Ex housing flame paths against original certification dimensions — flame paths must not be damaged, corroded, or modified. CA-FIRE provides a detailed hazardous-area-specific maintenance manual with every ZSFM-Ex shipment. Replacement piston seal kits are stocked for same-week despatch — contact sales@ca-fire.com with model and DN size.
Related Products
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Ex + Corrosion Resistant · SS316 · Air-Controlled Stainless Steel Deluge Valve When corrosion resistance is required in addition to Ex certification — offshore platforms, coastal facilities, chemical plants, marine environments. SS304/SS316 body with Ex-rated accessories and air-controlled (dry pilot) actuation option. View Stainless Steel Valve → |
Complete Station · Vertical · Ex-Rated Explosion-Proof Deluge Valve Skid The ZSFM-Ex valve assembled into a complete vertical skid station with all trim, gauges, and Ex control panel. Factory pressure-tested. Minimises hazardous area installation time. Zone 1/2 throughout. View Valve Skid → |
Complete Station · Horizontal · Factory-Tested Horizontal Deluge Valve Assembly Full factory-assembled horizontal skid: valve body, trim, isolation valves, gauges, Ex panel — pre-piped, pre-wired, pressure-tested. 3 site connections. BRI export documentation standard. View Assembly → |
Standard · Non-Hazardous Area · 1.6 MPa Diaphragm Deluge Valve The standard cast iron EPDM diaphragm deluge valve for non-classified areas — warehouses, power stations, airports, cable tunnels. DN50–DN350, 1.6 MPa, most competitively priced in the range. View Diaphragm Valve → |
Get a Quote — Explosion Proof Deluge Valve
ZSFM-Ex · 2.5 MPa · DN50–DN300 · Piston-Type · Ex db IIC T6 Gb / Ex tb IIIC T80°C Db · IP65
Zone 1 / Zone 2 · Zone 21 / Zone 22 | Water + AFFF/AR-AFFF 6% | GB 5135.7 · NFPA 13/15 · IEC 60079 · ISO 9001 · Factory Direct