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Aluminum EMCO Type Safety Pressure-Vacuum Breather Valve for Fuel Storage Tanks

Aluminum EMCO Type Safety Pressure-Vacuum Breather Valve for Fuel Storage Tanks

Maintaining stable internal pressure is a critical safety requirement for fuel storage tanks in gas stations and oil depots. The HYZQF Series Pressure-Vacuum Breather Valves are engineered to automatically regulate internal tank pressure, protecting storage systems from structural damage caused by excessive pressure build-up or vacuum conditions during loading, unloading, and temperature changes.

In different regions, this type of device is known by various names. In North America and Europe, it is commonly called a Pressure Vacuum Relief Valve, Tank Breather Valve, or PV Safety Valve. In the Middle East and Africa, it may be referred to as a Fuel Tank Vent Valve or Pressure Balance Valve. Asian markets often describe it as a Storage Tank Safety Breather or Pressure-Vacuum Control Valve. Despite the variation in terminology, all names describe the same essential function—maintaining pressure equilibrium while ensuring safe vapor exchange.

The HYZQF Series is typically installed on the vent pipe of above-ground fuel storage tanks at an installation height of approximately 4.5 meters. Under normal conditions, the valve remains sealed to preserve tank tightness. When internal pressure exceeds the preset positive threshold, the pressure section opens to release vapor. When negative pressure reaches the allowable limit, the vacuum section opens to allow fresh air intake, while the pressure side remains closed.

Constructed with an aluminum body and aluminum cap, the valve offers corrosion resistance and long service life in outdoor environments. A 40-mesh stainless steel screen is integrated to prevent water, debris, and insects from entering the tank ventilation system. Gasket options include Buna-N or Viton, allowing compatibility with different fuel types and operating conditions. The valve operates reliably within a temperature range of -20°C to +50°C.

For international markets, the positive pressure opening is set at +3 inches of water column (approximately +750 Pa), while the domestic Chinese standard is +9 inches of water column (approximately +3000 Pa). The negative pressure activation for both standards is -8 inches of water column (approximately -2000 Pa). This calibrated design helps reduce fuel evaporation losses while ensuring tank safety and regulatory compliance.

The HYZQF-XXFA models incorporate an additional flame arrestor, providing enhanced protection against external ignition sources. The flame arrestor housing is made of cast aluminum with a flange connection, and the internal arresting element uses foldable aluminum alloy material designed to effectively dissipate flame energy before it can reach the tank interior. This configuration makes the valve especially suitable for high-risk fuel storage environments.

Available connection options include BSPP or NPT female threads as well as aluminum flange connections ranging from 1.5 inches to 3 inches. Flange standards can be customized according to specific project or regional requirements. Installation is straightforward, and it is recommended to manually cycle the internal poppet before installation to ensure smooth operation after extended storage.

The HYZQF Series Pressure-Vacuum Breather Valves provide a reliable, low-maintenance solution for pressure regulation, vapor control, and safety protection in fuel storage applications. They are widely used in gas stations, oil depots, and other above-ground fuel storage facilities where operational safety and long-term reliability are essential.

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These vacuum pressure vent valves are used in gas stations or oil storage depots. The vent valve typically consists of two parts: a pressure valve and a vacuum valve designed to be installed inside. It is usually installed at a height of approximately 4.5 meters on the vent pipe of the oil storage tank to maintain the tank's tightness under normal circumstances.They protect tanks from excessive over or under pressure. The vent cap and internal wire screen are designed to protect the tank vent lines against intrusion and blockage from water, debris or insects. A normally closed poppet in the valve, opens at a predetermined pressure or vacuum setting to allow the tank to vent.



HYZQF-50 Vacuum
Pressure Vent Valve

Technique Specification:
Body: Aluminum
Cap: Aluminum
Screen: 40 Mesh Stainless steel mesh
Gasket: Buna-N or Viton for option
Temperature Range:-20~+50℃
Positive:+3 inches of water column for the international market + 9 inches of water column for the domestic market
Negative: -8 inches of water column

Order Specifications:

Model Connection Method
HYZQF-40 Female 1.5 inch Thread BSPP or NPT Standard (If necessary)
HYZQF-50 Female 2-inch Thread BSPP or NPT Standard (Regular Item)
HYZQF-50F 2-inch Aluminum Flange
HYZQF-65F 2.5-inch Aluminum Flange
HYZQF-80F 3-inch Aluminum Flange

Standard of connecting flange can be produced according to the client’s detailed requirements.

Important Note: These vents should not be used on an underground storage tank (UST) with a throughput of 100000 gallons or more per month.

Features:
It reduces oil evaporation losses to a certain extent. When necessary, it can automatically open and adjust to maintain a balanced pressure inside and outside the tank, serving a safety function for the tank.

When the vapor pressure in the tank exceeds the allowable pressure, oil vapor is released through the pressure valve, while the vacuum valve remains closed.

When the vapor pressure in the tank is lower than the allowable vacuum, fresh air enters the tank through the vacuum valve while the pressure valve stays closed.

The international standard for the positive pressure opening is +3 inches of water column (+750Pa), and the activation negative pressure is -8 inches of water column (-2000Pa). For the Chinese domestic market standard, the positive pressure opening is +9 inches of water column (+3000Pa), and the activation negative pressure is -8 inches of water column (-2000Pa).

Installation Instructions:
Before installing the PV vent, it is recommended to cycle the poppet up and down. This ensures free operation of the poppet if the valve has had an extended shelf life.

An inlet screen is now included with the Vacuum Pressure Vent Valve to avoid ingestion of particles from the riser pipe that could cause the valve poppet not to seal properly.

 

These vacuum pressure vent valves are used in gas stations or oil storage depots. The vent valve typically consists of two parts: a pressure valve and a vacuum valve designed to be installed inside. It is usually installed at a height of approximately 4.5 meters on the vent pipe of the oil storage tank to maintain the tank's tightness under normal circumstances. They protect tanks from excessive over- or under-pressure. The vent cap and internal wire screen are designed to protect the tank vent lines against intrusion and blockage from water, debris, or insects. A normally closed poppet in the valve opens at a predetermined pressure or vacuum setting to allow the tank to vent.



HYZQF-50FA Vacuum
Pressure Vent Valve
With Flame Arrestor

Technique Specification:
Body: Aluminum
Cap: Aluminum
Screen: 40 Mesh Stainless steel mesh
Gasket: Buna-N or Viton for option
Temperature Range:-20~+50℃
Positive:+3 inches of water column for the international market, + 9 inches of water column for the domestic market
Negative: -8 inches of water column
Flame Arrestor Body: Cast Aluminum (Flange Connection)
Inner Arrestor Material: Foldable Aluminum Alloy

Order Specifications:

Model Connection Method
HYZQF-50FA 2-inch Aluminum Flange
HYZQF-65FA 2.5-inch Aluminum Flange
HYZQF-80FA 3-inch Aluminum Flange

Standard of connecting flange can be produced according to the client’s detailed requirements.

Important Note: These vents should not be used on an underground storage tank (UST) with a throughput of 100000 gallons or more per month.

Features:
It reduces oil evaporation losses to a certain extent. When necessary, it can automatically open and adjust to maintain a balanced pressure inside and outside the tank, serving a safety function for the tank.

When the vapor pressure in the tank exceeds the allowable pressure, oil vapor is released through the pressure valve, while the vacuum valve remains closed.

When the vapor pressure in the tank is lower than the allowable vacuum, fresh air enters the tank through the vacuum valve while the pressure valve stays closed.

The international standard for the positive pressure opening is +3 inches of water column (+750Pa), and the activation negative pressure is -8 inches of water column (-2000Pa). For the Chinese domestic market standard, the positive pressure opening is +9 inches of water column (+3000Pa), and the activation negative pressure is -8 inches of water column (-2000Pa).

Installation Instructions:
Before installing the PV vent, it is recommended to cycle the poppet up and down. This ensures free operation of the poppet if the valve has had an extended shelf life.

An inlet screen is now included with the Vacuum Pressure Vent Valve to avoid ingestion of particles from the riser pipe that could cause the valve poppet not to seal properly.

 

 

About Haibo
Zhejiang Haibo Petroleum Equipment Co., Ltd.

Zhejiang Haibo Petroleum Equipment Co., Ltd., established in 2017, is a certified enterprise located in Yongjia County, Wenzhou City, Zhejiang Province—recognized globally as the world’s largest manufacturing base for petroleum equipment and the well-known hometown of pumps and valves in China.
Our products are widely used in Fluid Control Systems, Energy Systems, Measurement Systems, Piping Systems, and Hydraulic Systems, serving petroleum companies, military units, oil depots, tank truck manufacturers, and petrol stations worldwide. Province—recognized globally as the world’s largest manufacturing base for petroleum equipment and the well-known hometown of pumps and valves in China.
At Haibo, we are backed by a team of senior industry experts with more than 20 years of professional experience in the petroleum equipment and fluid control sectors. Their deep technical knowledge and industry insight ensure that every product and solution we deliver meets the highest standards of quality, reliability, and performance.

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