In industrial storage systems, maintaining the right tank pressure is essential for safety and efficiency. A Stainless Steel Breather Valve, also known as a Pressure Vacuum Relief Valve, automatically regulates pressure and vacuum to protect tanks from damage. As a professional breather valve manufacturer and supplier, ZhenChao provides reliable Stainless Steel Breather Valves designed for chemical, petroleum, and storage applications. The ZhenChao breather valve ensures stable operation, prevents vapor loss, and delivers long-lasting performance even in harsh environments.
A Breather Valve (or Pressure Vacuum Relief Valve) is a safety device installed on storage tanks and vessels that contain volatile or non-volatile liquids. Its primary function is to regulate the pressure inside the tank—allowing air to enter or exit when the pressure exceeds a set limit.
The Stainless Steel Breathing Valve variant is particularly valued for its durability and corrosion resistance, making it ideal for use in chemical plants, petroleum storage facilities, and food-grade applications.
Industrial tanks containing liquids such as oil, chemicals, or solvents are not designed to withstand extreme pressure or vacuum.
Pressure can build up or drop inside the tank because of:
Filling operations, which increase internal vapor pressure.
Liquid discharge, which creates negative pressure (vacuum).
Ambient temperature changes, which cause vapor expansion or contraction.
If uncontrolled, these conditions may lead to:
Tank deformation or explosion (due to overpressure)
Tank collapse (due to vacuum)
Increased product evaporation and environmental pollution
That’s where the breather valve—especially a Stainless Steel Breathing Valve—comes into play. It ensures that tanks “breathe” safely and automatically, maintaining a stable pressure balance.
When the liquid level rises during tank filling or when the temperature increases, the vapor inside expands, causing internal pressure to rise.
Once this pressure exceeds the preset limit, the pressure relief side of the breather valve opens automatically.
The internal tank pressure pushes upward on the pressure valve disc.
When the force exceeds the set spring or weight load, the disc lifts from its seat.
Excess vapors or gases are vented safely through the outlet to the atmosphere.
When the internal pressure returns to normal, gravity or spring force reseats the disc, sealing the valve.
Prevents tank rupture and gasket damage
Minimizes vapor loss by releasing only necessary pressure
Keeps the tank stable during product inflow or heat exposure
When the liquid level drops (during discharge) or the ambient temperature decreases, the vapor volume inside the tank contracts—creating a vacuum condition.
If not addressed, this negative pressure can cause the tank to buckle inward or damage structural integrity.
The vacuum valve disc senses pressure lower than the set limit.
Atmospheric air enters the tank through the valve.
The airflow equalizes internal and external pressure.
Once balance is restored, the disc reseats, preventing excess air or contamination.
Prevents tank collapse due to vacuum
Ensures continuous liquid discharge without pressure resistance
Maintains tank integrity and operational reliability
Most Stainless Steel Breather Valves—including the ZhenChao Breather Valve—are designed with dual-action functionality, combining both pressure and vacuum relief mechanisms in one unit.
Compact design requiring minimal installation space
Simultaneous control of both positive and negative pressure
Reduced maintenance with fewer moving parts
Stable tank pressure during all operational stages
This integrated approach ensures continuous safety protection during both filling and discharge, making it ideal for storage systems in chemical, petrochemical, and pharmaceutical industries.
Inside the Stainless Steel Breathing Valve, the structure typically includes:
Valve body: Constructed from SS304 or SS316 for corrosion resistance
Pressure disc assembly: Opens during overpressure conditions
Vacuum disc assembly: Opens during vacuum conditions
Sealing gaskets: Ensure tight closure and leak-free operation
Protective mesh or flame arrestor (optional): Prevents flame propagation
Under normal conditions, both discs remain closed, keeping the tank sealed.
Under overpressure, the pressure disc opens to discharge vapor.
Under vacuum, the vacuum disc opens to draw air in.
This cycle happens automatically, allowing the tank to “breathe” efficiently with minimal product loss.
Every breather valve has a preset pressure range, calibrated to the specific tank design and fluid type.
Typical set points:
Pressure Opening Range: +20 mbar to +50 mbar
Vacuum Opening Range: −20 mbar to −50 mbar
ZhenChao Stainless Steel Breather Valves are factory-calibrated with high precision, ensuring accurate response to pressure fluctuations while minimizing unnecessary venting. Custom pressure settings are also available for different tank systems and applications.
When the internal pressure returns to normal, the Stainless Steel Breathing Valve automatically reseals.
The valve’s stainless steel seat and disc are finely machined to achieve tight closure, while sealing gaskets (PTFE, Viton, or rubber) prevent vapor leakage.
Zero leakage under normal operation
Enhanced emission control and environmental compliance
Long service life with minimal maintenance
The ZhenChao Breather Valve is particularly known for its precision sealing design, offering reliable performance even in corrosive chemical or fuel applications.
For hazardous environments like petroleum and solvent tanks, ZhenChao Breather Valves can be equipped with a flame arrestor.
This component prevents external flames from entering the tank through the vent, offering an extra layer of protection.
The flame arrestor mesh dissipates heat from the flame front.
The flame is extinguished before it can pass through.
Normal breathing (pressure/vacuum operation) continues unaffected.
This combination of flame arresting and pressure control makes ZhenChao Stainless Steel Breather Valves ideal for use in fire-prone or flammable storage environments.
In summary, the Stainless Steel Breathing Valve ensures the safety, stability, and efficiency of any closed storage tank. It automatically releases excess pressure, admits air when vacuum occurs, and remains sealed when conditions are normal—providing a complete breathing cycle. The ZhenChao Breather Valve stands out for its precision engineering, stainless steel durability, and advanced sealing design, making it a trusted solution for industries that demand reliability and safety in every operation.
