Safety Valves | McMaster-Carr

	Inlet Pipe Size Inlet Pipe Size

	For Use With For Use With

	Valve Function Valve Function

Pressure Relief

On/Off

Back-Pressure Regulation

Directional Control

Temperature Regulation

Diverting

	Inlet Thread Type Inlet Thread Type

	Maximum Inlet Pressure Maximum Inlet Pressure

	Relief Port Pipe Size Relief Port Pipe Size

	Body Material Body Material

	Seal Material Seal Material

	Inlet Gender Inlet Gender

Male

Female

	Set Pressure Configuration Set Pressure Configuration

Nonadjustable

Adjustable

	Shape Shape


90° Elbow	Straight

Tee	Wye

	Valve Type Valve Type

Back-Pressure Regulator

Temperature Regulator

Thermostatic Mixing

	Maximum Temperature Maximum Temperature

	Test Mechanism Test Mechanism

Lever

Ring

T-Handle

	Overall Height Overall Height

	Relief Port Connection Type Relief Port Connection Type

Pipe

Vent

	Specifications Met Specifications Met

3-A Sanitary Certified

ANSI

ANSI/FCI 70-2 Class III

	Inlet Connection Type Inlet Connection Type


Pipe	Tube

	Activation Activation

Pressure Driven

Temperature Driven

Manual

	Inlet Connection Style Inlet Connection Style

	Relief Port Location Relief Port Location

Side

Top

Bottom

	RoHS (Restriction of Hazardous Substances) RoHS (Restriction of Hazardous Substances)

RoHS Compliant with
Exemptions

RoHS Compliant

	REACH (Registration, Evaluation, Authorization and Restriction of Chemicals) REACH (Registration, Evaluation, Authorization and Restriction of Chemicals)

REACH Compliant

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697 Products

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.

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.

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 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.

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.

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.

Fast-Acting Pressure-Relief
Valves for Cryogenic Liquids

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

Pressure-Relief Valves

Pressure-Relief Valves for Water

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

Adjustable Pressure-Relief Valves for Water

Alter the set pressure to suit your application.

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.

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 from 150 to 3,300 psi.

Precision-Adjustment Pressure-Relief Valves for Fuel

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

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.

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 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.

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 Chemicals

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

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.

Pressure-Relief Valves for Oil

These valves are often used in hydraulic and lubrication systems.

Back-Pressure-Regulating Valves

Extended-Life Back-Pressure-Regulating
Valves for Water and Oil

For a longer service than cast iron valves, these have a durable bronze body and a 303 stainless steel seal.

Back-Pressure-Regulating Valves for Water and Oil

These valves have a cast iron body.

Back-Pressure-Regulating Valves for Air and Inert Gas

Use these valves in pipelines.

Panel-Mount Back-Pressure-Regulating
Valves for Air and Inert Gas

Threads below the adjustment knob and an included panel-mount nut allow you to add these valves to your instrument panel.

Sanitary Back-Pressure-Regulating Valves

Designed to meet 3-A sanitary standards, these valves regulate liquid, gas, and air pressure in hygienic zones of food and beverage plants.

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.

Threaded Pressure-Relief Discs

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

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.

Flange-Mount Pressure-Relief Discs

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

Compressed Air Control Valves

Safety-Lockout Air On/Off Valves

A padlock locks the handle of these valves in the shut-off position so you can disconnect air tools safely.

Quiet Safety-Lockout Air On/Off Valves

These valves have a muffler to reduce exhaust noise. A padlock locks the handle in the shut-off position so you can disconnect air tools safely.

Air-Operated Air On/Off Valves

Also known as blocking valves, these valves allow airflow while an air signal is applied to the air pilot. When the signal stops, the valve closes, trapping air in the system.

High Airflow Shut-Off On/Off Valves

Also known as air fuses, these valves close automatically to turn airflow off when air volume exceeds the shut-off flow rate.

Safety-Lockout Single-Action
Air Directional Control Valves

To prevent accidental start-up, these valves can be locked in their off position with a padlock. They create one action, such as extending a cylinder.