The HX3/HXF3 breather valve with suction nozzle is a two-way breather valve installed on the top of fixed roof tanks, featuring an independent suction nozzle (for connecting nitrogen or other blanketing gas) and a venting passage, integrating pressure relief, safe vacuum intake, and flame arrestor functions. When the tank pressure exceeds the set value, the pressure disc opens to discharge volatile vapors through the flame arrestor to the atmosphere or a recovery system; when vacuum occurs inside the tank, the vacuum disc opens to introduce blanketing gas (e.g., nitrogen) or air through the suction nozzle, rapidly restoring tank pressure. Its core purpose is to automatically supply dry inert gas via the suction nozzle during tank discharging or sudden temperature drops, preventing air from entering the tank and forming explosive mixtures, while also providing overpressure relief and flame arrestor protection to ensure tank safety and product quality.

HX3 and HXF3 breather valves with connection pipe product diagram

1. Independent suction nozzle design: Dedicated suction nozzle can be connected to a nitrogen supply line or air filter for controlled gas intake, preventing direct ingress of humid air or dust during tank vacuum conditions.

2. Two-way breathing function: Pressure disc and vacuum disc operate independently for overpressure relief and vacuum intake; pressure settings adjustable as required.

3. Built-in flame arrestor: Stainless steel corrugated plate flame arrestor core effectively blocks flame propagation, meeting petrochemical tank fire protection standards.

4. Set-pressure operation with reliable sealing: Flat or tapered hard seal ensures stable opening pressure and zero leakage when closed.

5. All-weather protection structure: Rain and dust cover with internal drainage prevents water accumulation, suitable for harsh outdoor environments.

6. Corrosion-resistant materials: Body available in aluminum alloy, cast steel, or stainless steel; discs and flame arrestor core in stainless steel for various corrosive media.

7. Large ventilation capacity with low pressure drop: Optimized flow path provides low breathing resistance for both venting and gas intake during rapid tank filling or discharging.

8. Easy maintenance: Removable flame arrestor core for cleaning; simple disc assembly disassembly; suction nozzle with standard interface for easy connection.

HX3 type with suction connection breathing valve DN50-250        HXF3 type with suction connection flame retardant breathing valve DN50-250

Drawing of Parts

Performance Specification Table

Operation Pressure Reference Table

HX3 type with suction connection breathing valve DN50-250        HXF3 type with suction connection flame retardant breathing valve DN50-250

Outline dimension table

Due to the rapid R&D iteration speed of valve products from China kaiweixi Valve Group Co., Ltd., the above technical parameters and specification documents, including product overview, features, parts materials, outline dimension charts, CAD drawings, and product instruction manuals, are for your reference only. For actual applications, please contact our valve sales engineers to obtain the support you need for free. Thank you!