The HX-4/HXF-4 breather valve with dual nozzles is a two-way breather valve specifically designed for fixed roof storage tanks. It features two independent piping connections (dual nozzles) respectively for “overpressure relief” and “vacuum intake”. When tank pressure rises, the pressure disc automatically opens and gas is discharged through one nozzle to a recovery network; when vacuum occurs, the vacuum disc opens and nitrogen or purified air is admitted through the other nozzle. A stainless steel corrugated flame arrestor can be installed inside to prevent external flame ingress. Its core purpose is to achieve separated breathing management – centralized recovery of vent gas and controlled gas intake, meeting the combined requirements of vapor recovery, nitrogen blanketing, and fire/explosion protection.

HX-4 and HXF-4 breathing valves with dual connection pipes product diagram

Features:

1. Dedicated dual‑nozzle functions – Vent nozzle exclusively for discharge; intake nozzle exclusively for gas supply, avoiding interference.

2. Set‑pressure operation with reliable sealing – Pressure and vacuum discs open independently at their set values; tapered hard seal ensures zero leakage after reseating.

3. Optional flame arrestor – Built‑in stainless steel corrugated plate element quenches flames in both directions, meeting tank fire safety codes.

4. High ventilation capacity, low resistance – Optimized flow path provides low breathing resistance, suitable for rapid filling/emptying with high flow rates.

5. Multiple corrosion‑resistant materials – Housing available in aluminum alloy, carbon steel, or stainless steel; internal parts in stainless steel, suitable for oil, solvents, and chemicals.

6. All‑weather protection – Top rain cover, insect screen, and internal drainage slots prevent ingress of rain and debris.

7. Easy maintenance – Disc assembly can be removed as a whole; the optional flame arrestor element can be pulled out for cleaning without hot work or pipeline disassembly.