Vacuum Relief / Breather Valve
Tank breathing valve that opens on vacuum or pressure to protect storage tanks from over- or under-pressure.
Technical Specifications
| Type | Pressure & Vacuum Relief (PVR) |
| Size Range | 1" to 8" (25 mm to 200 mm) |
| Body Materials | Aluminium, Carbon Steel, Stainless Steel, FRP |
| Pallet | SS316 with PTFE seat |
| Set Points | Pressure: +0.5 to +150 mbar / Vacuum: -0.5 to -60 mbar |
| End Connections | Flanged (nozzle mount) |
| Standards | API 2000,ISO 28300 |
| Lead Time | Ex-stock Gujarat: Same day | Standard items: 2–4 weeks | Exotic alloys: 8–12 weeks |
Applications
Storage tanks, API tanks, chemical vessels, gasoline terminals
About the Vacuum Relief / Breather Valve
The pressure/vacuum relief valve (PVRV), commonly called a breather valve or conservation vent, is a dual-function device mounted directly on the vent nozzle of atmospheric or low-pressure fixed-roof storage tanks. It serves as the primary overpressure and vacuum protection device for tanks storing petroleum products, chemicals, and liquefied gases that would otherwise be exposed to tank collapse (vacuum) or roof rupture (pressure) from liquid inflow/outflow, diurnal temperature cycling, or product loading and unloading operations. The breather valve allows the tank to "breathe" - releasing vapours when tank pressure exceeds the pressure set point, and admitting air when the tank volume contracts below the vacuum set point - while remaining hermetically closed during normal operations to minimise evaporative losses.
The pressure pallet and vacuum pallet are independent weighted discs (or spring-loaded pallets for higher set points) sitting on precision machined seats. The pallet weights (or spring ratings) directly determine the set pressure and vacuum set points, which are specified per API 2000 / ISO 28300 breathing rate calculations based on tank diameter, stored product, and thermal and operational breathing rates. Vapour conservation is a primary driver - minimising the quantity and frequency of vent openings reduces VOC emissions and product losses. Vajra Industrial Solutions supplies breather valves in Aluminium, Carbon Steel, SS316, and FRP body materials sized to API 2000.
Where It's Used
Key industries and applications for the Vacuum Relief / Breather Valve
Petroleum product storage tanks
API 2000 aluminium or Carbon Steel PVRVs on fixed-roof tanks storing crude oil, naphtha, gasoline, diesel, and jet fuel at petroleum refineries, pipeline terminals, and aviation fuel depots; low set pressures (+14 to +35 mbar / -3.5 mbar) minimise vapour losses
Chemical storage vessels
SS316 or FRP breather valves on fixed-roof atmospheric vessels storing solvents, acids, alkalis, and other chemicals; PTFE or FKM pallet seat for chemical compatibility; flame arrestor integral option for flammable vapour service
Edible oil and food-grade storage
SS316 PVRVs with PTFE seats and FDA-compliant materials on edible oil, vegetable oil, and food-grade liquid storage tanks; easy-clean design for hygiene compliance
Water storage tanks and distribution reservoirs
Aluminium or Carbon Steel vacuum relief valves (vacuum-only, no pressure relief) on closed-top water storage tanks and pressure vessels to prevent vacuum collapse during pump-out
Gasoline and solvent terminal loading racks
high-capacity PVRVs on bulk storage tanks at fuel and solvent terminals; sized for maximum filling rate breathing capacity per API 2000 Table 1; vapour return line connections reduce VOC emissions during truck loading
How to Choose the Right Vacuum Relief / Breather Valve
Size a breather valve using API 2000 / ISO 28300 to determine the required in-breathing (vacuum) and out-breathing (pressure) capacity at the defined set pressure and vacuum set points. The breathing rate depends on tank diameter, maximum filling and emptying pump rates, and thermal breathing (diurnal temperature change). Always verify that the selected body size provides the required flow at the set pressure without exceeding 20% overpressure at maximum flow - this is the "lift-to-full-open" criterion. Specify PTFE pallets and seats for chemical or solvent service; standard pallets for petroleum products.
Popular Configurations
Most commonly ordered specifications for the Vacuum Relief / Breather Valve
Frequently Asked Questions
About Vacuum Relief / Breather Valve - ordering, specs, delivery & compliance
What standards does the Vacuum Relief / Breather Valve comply with?+
Our Vacuum Relief / Breather Valve complies with API 2000, ISO 28300. All products are manufactured to international standards and come with full material test reports (MTR), dimensional inspection reports, and hydrostatic test certificates on request.
What materials are available for the Vacuum Relief / Breather Valve?+
The Vacuum Relief / Breather Valve is available in Aluminium, Carbon Steel, Stainless Steel, FRP. Material selection depends on your process fluid, temperature, pressure, and corrosion requirements.
What is the delivery lead time for Vacuum Relief / Breather Valve?+
Standard stock sizes are available for immediate dispatch from our Vadodara warehouse. Custom sizes and special materials typically have a lead time of 2–6 weeks depending on specifications. We serve customers across India within 1–7 business days and export to the Middle East, Southeast Asia, Europe, and the Americas with full export documentation.
Can I get a custom Vacuum Relief / Breather Valve for a specific application?+
Yes. Vajra Industrial Solutions supplies custom-engineered safety & relief valves for specific process conditions. Submit your technical requirements - including pressure class, temperature range, fluid type, end connections, and any special trim or coating needs - via our RFQ form or WhatsApp, and our engineering team will respond within 24 hours.
What pressure ratings are available for the Vacuum Relief / Breather Valve?+
The Vacuum Relief / Breather Valve is available in pressure ratings of PN10 to PN400 (ANSI Class 150 to Class 2500). Higher-pressure classes are available for critical service applications in oil & gas, power generation, and chemical processing.
How do I request a quote for the Vacuum Relief / Breather Valve?+
You can request a quote by clicking the "Request Quote" button on this page, filling out our RFQ form at vajravyuh.com/rfq, emailing us at sales@vajravyuh.com, or WhatsApping us directly at +91-9979774557. Please include quantity, size, pressure class, material grade, and end-connection type for the fastest response.
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