Hose Check Valves | McMaster-Carr

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	For Use With For Use With

Acetylene

Air

	Thread Type Thread Type

NPT

UNF

GHT

	Pipe Size Pipe Size

1/4

	System of Measurement System of Measurement

Inch

	Thread Size Thread Size

3/8"-24

9/16"-18

3/4"

	Connection Type Connection Type	Show

	Hose

	Connection Type Connection Type	Hide


Pipe	Tube

Hose

	Connection Style Connection Style

	Threaded

	Material Material

Brass

	Gender Gender

Female

Male

	Mounting Orientation Mounting Orientation

Horizontal

Vertical

Any Position

	Thread Direction Thread Direction

Right Hand

Left Hand

	Component Component

Check Valve

Flashback Arrester

	DFARS (Defense Acquisition Regulations Supplement) DFARS (Defense Acquisition Regulations Supplement)

DFARS Specialty Metals
COTS-Exempt

	Specifications Met Specifications Met

ASME

ASSE

CSA

European Safety
Specification EN730

ISO

NSF/ANSI

UPC

	Connection Connection

Inlet

Outlet

	Body Material Body Material

Brass

	Valve Function Valve Function

Backflow Prevention

	Maximum Pressure Maximum Pressure

125 psi @ 70° F

	Fitting Type Fitting Type

	Adapter

	Shape Shape

	Straight

	Valve Type Valve Type

Vacuum Breaker

	Maximum Temperature Maximum Temperature

Less than 200° F

	End-to-End Length End-to-End Length

1 1/2"

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20 Products

About Backflow-Prevention Valves

With Set Screw

With Tamper-Resistant Set Screw

For Use With: Air, Water
Seal Material: Rubber

Prevent dirty, contaminated water from backing up into your garden hose line—install these valves between a faucet and a garden hose. Also known as vacuum breakers, these valves have a built-in check valve that blocks backflow, so you can leave your hose in a utility sink full of dirty water without the water going back into the line.

When the check valve is closed, it has vents that open to release the water. This reduces pressure in the line and confirms the valve is working. Because these valves vent water, use them in environments where spilled water won’t cause a problem. This design adheres to ASSE Standard 1011 for valves with a vent.

Mount valves to faucet outlets with a set screw, and easily thread or unthread a hose while the valves stay in place.

Valves comply with Uniform Plumbing Code (UPC) and are CSA certified, so they're safe to use in sanitary plumbing systems because they prevent contamination from flowing backward into your line.

These valves are designed to be used intermittently. They've been tested under ASME A112.1.3, which assumes the valves will not be used for more than 12 hours at a time.

Chrome-plated brass valves are more corrosion resistant than plain brass valves.

Valves with tamper-resistant set screws have a head that breaks off after tightening to prevent valve removal after installation.

Valves that meet NSF/ANSI Standard 372 are certified lead free.

					Brass Body		Chrome-Plated Brass Body
Thread Size	Max. Pressure	Temperature Range, °F	End-to-End Lg.	Specifications Met		Each		Each
GHT Female × GHT Male
With Set Screw
3/4"	125 psi @ 70° F	30° to 180°	1 1/2"	ASSE Standard 1011, Uniform Plumbing Code, CSA Certified, CAN/CSA B64.2, ASME A112.1.3	00000000	000000	00000000	000000
3/4"	125 psi @ 70° F	30° to 180°	1 1/2"	ASSE Standard 1011, Uniform Plumbing Code, CSA Certified, CAN/CSA B64.2, NSF/ANSI 372, ASME A112.1.3	00000000	00000	00000000	00000
With Tamper-Resistant Set Screw
3/4"	125 psi @ 70° F	30° to 180°	1 1/2"	ASSE Standard 1011, Uniform Plumbing Code, CSA Certified, CAN/CSA B64.2, ASME A112.1.3	00000000	00000	00000000	00000
3/4"	125 psi @ 70° F	30° to 180°	1 1/2"	ASSE Standard 1011, Uniform Plumbing Code, CSA Certified, CAN/CSA B64.2, NSF/ANSI 372, ASME A112.1.3	00000000	00000	00000000	00000

Welding Gas Check Valves for Regulators

Stop the reverse flow of gas in your regulator. Check valves do not stop flashbacks.

Max. Pressure, psi				Male Hose Connection			Male Pipe Connection
Oxygen	Acetylene	Hydrogen	Propane	Thread Direction	Thread Size	Thread Type	Thread Direction	Pipe Size	Thread Type	Material		Each
125	__	__	__	Right Hand	9/16"-18	UNF	Right Hand	1/4	NPT	Brass	000000	000000
__	50	50	50	Right Hand	9/16"-18	UNF	Left Hand	1/4	NPT	Brass	000000	00000

Welding Gas Check Valves for Torches

Stop the reverse flow of gas in your torch. Check valves do not stop flashbacks.

Max. Pressure, psi				Male Hose Connection			Female Hose Connection
Oxygen	Acetylene	Hydrogen	Propane	Thread Direction	Thread Size	Thread Type	Thread Direction	Thread Size	Thread Type	Material		Each
125	__	__	__	Right Hand	3/8"-24	UNF	Right Hand	3/8"-24	UNF	Brass	000000	000000
125	__	__	__	Right Hand	9/16"-18	UNF	Right Hand	9/16"-18	UNF	Brass	000000	0000
__	50	50	50	Left Hand	3/8"-24	UNF	Left Hand	3/8"-24	UNF	Brass	000000	00000
__	50	50	50	Left Hand	9/16"-18	UNF	Left Hand	9/16"-18	UNF	Brass	000000	0000

Welding Gas Flashback Arresters for Torches

These arresters attach directly to torches that cut steel up to 8" thick. They extinguish flames and have a check valve to stop reverse gas flow. They are reusable; resetting is not required after flashback.

Arresters with right-hand threads are for use with oxygen; arresters with left-hand threads are for use with acetylene, hydrogen, and propane.

With Right-Hand Threads

	Male Hose Connection		Female Hose Connection
Max. Pressure for Oxygen, psi	Thread Size	Thread Type	Thread Size	Thread Type	Material	Specifications Met		Each
143	9/16"-18	UNF	9/16"-18	UNF	Brass	European Safety Specification EN730, ISO 5175 Class 1	00000000	000000

With Left-Hand Threads

Max. Pressure, psi			Male Hose Connection		Female Hose Connection
Acetylene	Hydrogen	Propane	Thread Size	Thread Type	Thread Size	Thread Type	Material	Specifications Met		Each
15	50	50	9/16"-18	UNF	9/16"-18	UNF	Brass	European Safety Specification EN730, ISO 5175 Class 1	00000000	000000

With Right-Hand and Left-Hand Threads

Max. Pressure, psi				Male Hose Connection		Female Hose Connection
Oxygen	Acetylene	Hydrogen	Propane	Thread Size	Thread Type	Thread Size	Thread Type	Material	Specifications Met		Pair
143	15	50	50	9/16"-18	UNF	9/16"-18	UNF	Brass	European Safety Specification EN730, ISO 5175 Class 1	00000000	000000

Welding Gas Flashback Arresters for Regulators

Attach these arresters to the outlet connection of a regulator on a torch that cuts steel up to 11" thick. Arresters extinguish flames and have a check valve to stop reverse gas flow. They are reusable; resetting is not required after flashback.