Integrated Flame-Arrest Pressure Vacuum Breather Valve – For Aboveground Fuel Storage Tanks
In fuel storage systems where flammable vapors are constantly present, pressure control alone is not enough. Protection against ignition sources is equally critical. The HY625Z-XX Series Pressure Vacuum Breather Valve with Built-in Flame Arrestor is specifically designed to provide both pressure regulation and flame protection in a single compact unit, making it ideal for gas stations, oil depots, and aboveground fuel storage tanks.
Across different regions, this type of valve is known under various names. In international markets, it is commonly referred to as a Pressure Vacuum Breather Valve, PV Safety Valve, or Tank Vent Valve with Flame Arrestor. In Europe, it may be called a Pressure-Vacuum Relief Valve with Integrated Flame Trap, while in Russia, the Middle East, and parts of Asia, users often describe it as an Explosion-Proof Tank Breathing Valve. Regardless of terminology, the core function remains the same: maintaining safe tank pressure while preventing flame propagation.
The HY625Z-XX series is typically installed on the vent pipe at the top of aboveground storage tanks, with a recommended height of approximately 4.5 meters. Under normal conditions, the valve remains closed to preserve tank tightness and minimize vapor loss. When internal pressure rises due to temperature changes or loading operations, the pressure side of the valve opens automatically to release excess vapor. When negative pressure occurs during unloading or cooling, the vacuum side opens to allow air intake, while the pressure valve stays sealed. This balanced operation protects the tank structure from deformation or collapse.
What distinguishes the HY625Z-XX series is its built-in flame arrestor design. Unlike external flame arrestors that increase installation height and maintenance complexity, this valve integrates the flame arresting element directly into the valve body. The foldable aluminum arrestor element effectively stops flame transmission while maintaining smooth airflow. Combined with a stainless-steel cap and robust aluminum body, the valve offers reliable fire protection without sacrificing ventilation performance.
The valve is engineered to meet both international and domestic pressure standards. For global markets, the positive pressure opening is calibrated at +3 inches of water column (≈ +750 Pa), while the negative pressure activation is -8 inches of water column (≈ -2000 Pa). For the Chinese domestic market, the positive pressure setting is +9 inches of water column (≈ +3000 Pa), with the same negative pressure threshold. These precise settings help reduce evaporation losses while ensuring tank safety under varying operating conditions.
Connection flexibility is another advantage of the HY625Z-XX series. The standard configuration uses a 2-inch aluminum flange, with optional female NPT or BSP threaded connections (1.5 inch or 2 inch) as required. Custom flange standards can also be manufactured to match specific project requirements, making the valve suitable for both new installations and retrofit projects.
Before installation, it is recommended to manually actuate the poppet to confirm smooth movement, especially if the valve has been stored for an extended period. An integrated inlet screen helps prevent foreign particles from entering the valve body, ensuring reliable sealing and long service life.
By combining pressure relief, vacuum protection, and flame arresting functions into one compact unit, the HY625Z-XX Series Integrated Flame-Arrest Pressure Vacuum Breather Valve delivers a high level of safety and operational efficiency for modern fuel storage facilities, particularly in environments where explosion prevention is a top priority.
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