Pressure Relief Valves | McMaster-Carr

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About Pressure-Relief Valves

ASME-Code Fast-Acting Pressure-Relief
Valves for Air and Inert Gas

Body is brass or nickel-plated brass. All meet ASME Code Section VIII for use with air and inert gas pressure vessels.

Fast-Acting Pressure-Relief Valves for Air and Inert Gas

The most basic option for air and inert gas applications.

Corrosion-Resistant ASME-Code Fast-Acting
Pressure-Relief Valves for Air and Inert Gas

For corrosion resistance in wet conditions and harsh environments, these valves have a 303 stainless steel body. All meet ASME Code Section VIII for use with air and inert gas pressure vessels.

Remote-Discharge ASME-Code Fast-Acting
Pressure-Relief Valves for Air and Inert Gas

These valves have a bronze body for durability and a long service life. All meet ASME Code Section VIII for use with air and inert gas pressure vessels.

Corrosion-Resistant Remote-Discharge ASME-Code
Fast-Acting Pressure-Relief Valves for Air and Inert Gas

With a 316 stainless steel body for exceptional corrosion resistance, these valves are often used in wet conditions and harsh environments. All meet ASME Code Section VIII for use with air and inert gas pressure vessels.

Large-Diameter Remote-Discharge Fast-Acting
Pressure-Relief Valves for Air and Inert Gas

Commonly used with high-volume blowers, compressors, and air-powered conveyors, these valves quickly relieve a large amount of air in systems with a pipe size of 2 or greater.

Large-Diameter Remote-Discharge ASME-Code
Fast-Acting Pressure-Relief Valves for Air and Inert Gas

Commonly used with high-volume blowers, compressors, and air-powered conveyors, these valves quickly relieve a large amount of air in systems with a pipe size of 2 or greater. All meet ASME Code Section VIII for use with air and inert gas pressure vessels.

Adjustable Fast-Acting Pressure-Relief
Valves for Air and Inert Gas

Change set pressure to suit your application—this valve includes four interchangeable color-coded springs with different set pressure ranges.

Fast-Acting Pressure-Relief
Valves for Air with Gauge Port

Attach a pressure gauge to the 1/4 NPT female port on these valves.

ASME-Code Fast-Acting
Pressure-Relief Valves for Steam

These valves meet ASME Code Section I for use with steam power boilers requiring pressure relief above 15 psi.

ASME-Code Fast-Acting Pressure-Relief
Valves for Low-Pressure Steam

For use with low-pressure steam-heating boilers requiring pressure relief at 15 psi, these valves meet ASME Code Section IV.

Fast-Acting Pressure-Relief Valves
for Ultra-Low-Pressure Steam

Choose these valves for small steam-heating boilers requiring pressure relief between 5 psi and 12 psi.

Fast-Acting Pressure-Relief
Valves for Cryogenic Liquids

Use these valves with liquid argon, liquid nitrogen, and liquid oxygen.

ASME-Code Fast-Acting Pressure-Relief
Valves for Cryogenic Fluids

Our only valves that meet ASME Code Section VIII for use with cryogenic pressure vessels. They are for use with argon, carbon dioxide, helium, hydrogen, methane, nitrogen, and oxygen.

ASME-Code Fast-Acting
Pressure-Relief Valves for Hot Water

Protect your water-heating system with these valves that meet ASME Code Section IV for hot water heaters and boilers.

ASME-Code Fast-Acting
Pressure-Relief Valves for Water

These valves meet ASME Code Section VIII for use with water pressure vessels.

Fast-Acting Temperature- and
Pressure-Relief Valves for Hot Water

Also known as T & P valves, these open when water temperature reaches 210° F or at the set pressure.

Pressure-Relief Valves

Pressure-Relief Valves with
Push-to-Connect Fittings for Air

For a low-pressure seal around plastic and soft metal tubing, these valves have push-to-connect fittings.

Compact Pressure-Relief Valves

Less than a quarter of the height of standard pressure-relief valves, these are often installed on tanks in low-clearance areas.

Pressure-Relief Valves for Cryogenic Applications

Cleaned and bagged for oxygen service and other high-purity applications, these valves are built to withstand the extreme cold of liquid carbon dioxide, liquid nitrogen, and liquid oxygen.

Adjustable Pressure-Relief Valves for Water

Alter the set pressure to suit your application.

Pressure-Relief Valves for Water

These valves are commonly used with pumps in low-pressure water systems.

Precision-Adjustment Pressure-Relief Valves for Water

Change set pressure without guesswork—the adjustment screw is marked in 25 psi increments for making pressure adjustments without a gauge.

Adjustable Inline Pressure-Relief Valves for Chemicals

With a three-port design, these valves allow inline flow from the inlet to the outlet during normal conditions and divert flow through the relief port in overpressure conditions. They are often used with feed pumps for fertilizers and bleach.

Adjustable Pressure-Relief Valves for Chemicals

These valves are often used with catalysts, pH buffers, and electroplating solutions.

Adjustable Pressure-Relief Valves for Fuel

To gradually relieve pressure in lines for diesel fuel, fuel oil, gasoline, and kerosene, these valves begin opening at the set pressure and fully open at about 10% over the set pressure.

Precision-Adjustment Pressure-Relief Valves for Fuel

A finely threaded adjustment screw lets you make precise set pressure adjustments.

Made-to-Order Pressure-Relief Valves

Design a valve specifically for your process media and set pressure. Choose from a valve for air, inert gas, water, hydraulic oil, fuel oil, gasoline, or diesel fuel and a set pressure.

Pressure-Relief Valves for Oil

These valves are often used in hydraulic and lubrication systems.

Air-Release Valves

Corrosion-Resistant Remote-Discharge
Air-Release Valves for Water

For excellent corrosion resistance in wet conditions and harsh environments, these valves have no metal parts.

Remote-Discharge Air-Release Valves for Water

These valves have a cast iron body.

Air-Release Valves for Water and Coolant

Body is brass.

Corrosion-Resistant Air-Release
Valves for Water and Coolant

These valves are made of corrosion-resistant materials for use in wet conditions and harsh environments.

Inline Air-Release Valves for Water

An internal wire brush traps air bubbles and discharges them through the top relief port while allowing inline flow from the inlet to the outlet.

Key-Operated Air-Release Valves for Water

Turn the key to manually vent radiators and heaters.

Air-Release Valves for Oil and Fuel

Use this valve with oil, diesel fuel, gasoline, and kerosene.

Air-Release Valves for Drinking Water

Eliminate air pockets in your drinking water system with these valves. They meet NSF/ANSI 61, which designates them as safe to use with drinking water.

Air-Release Valves for Steam

Our only air-release valves for steam, these seal shut when steam enters the valve to prevent system contents from escaping through the relief port.

Pressure-Relief Discs

Remote-Discharge Threaded Pressure-Relief Discs

Instead of exhausting discharge directly, these discs have a threaded relief port for attaching a drain line to direct discharge away from your work environment.

Heat-Activated Threaded Pressure-Relief Discs

Also known as fusible plugs, these discs have a metal core that melts at a set temperature to exhaust discharge directly.

Threaded Pressure-Relief Discs

These valves have a vented relief port to exhaust discharge directly.

Flange-Mount Pressure-Relief Discs

Install these discs within the bolt circle of ANSI Class 150 flanges.

Hydraulic Valves

Pressure-Relief Block-Mount Hydraulic Valves

Set a specific pressure and these valves will maintain it by diverting excess fluid to a tank.

Pressure-Relief Screw-In Hydraulic Valves

Set a specific pressure and these valves will maintain it.

Pressure-Relief Hydraulic Valves

To set the pressure, unscrew the cap and turn the adjusting screw.

Easy-Adjust Pressure-Relief Hydraulic Valves

An external nut lets you adjust the pressure without disassembling the valve.

Tamper-Resistant Pressure-Relief Hydraulic Valves

The pressure setting on these valves cannot be adjusted while they are installed.