Valves for Hydrogen | McMaster-Carr

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For Use With

Hydraulic Fluid (Petroleum Based)

Methyl Ethyl Ketone (MEK)

Sodium Bicarbonate (Baking Soda)

Sodium Carbonate (Soda Ash)

Sodium Chloride

Sodium Hydroxide (Caustic Soda)

Sodium Hypochlorite (Bleach)

Toluene (Methylbenzene)

System of Measurement

Outlet Pressure

Pipe Size

Inlet Pipe Size

Body Material

Maximum Inlet Pressure

500 psi to 999 psi

2,000 psi to 3,999 psi

Valve Function

Maximum Temperature

Thread Type

Relief Port Pipe Size

3/4

Maximum Pressure

Less than 1,000 psi

1,000 psi to 1,999 psi

3,000 psi to 3,999 psi

Connects To

Inlet Thread Type

Maximum Outlet Pressure Gauge Measurement

Seal Material

Outlet Pipe Size

Minimum Temperature

Inlet CGA Number

RoHS

Compliant with Exemptions

Not Compliant

U.S.–Mexico–Canada Agreement (USMCA) Qualifying

Yes

DFARS Specialty Metals

Exempt

REACH

Compliant

Not Compliant

Export Control Classification Number (ECCN)

EAR99

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30 Products

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

These valves meet ASME Code Section VIII for use with cryogenic pressure vessels. Rated for use with argon, carbon dioxide, helium, hydrogen, methane, nitrogen, and oxygen, they are cleaned and bagged for oxygen service and other high-purity applications. All spring fully open at the set pressure and remain open until the system pressure is restored below the set pressure. Attach a drain line to the threaded relief port for remote discharge.

NPT Male Inlet and NPT Female Relief Port

Inlet			Relief
Pipe Size	Location	Max. Pressure, psi	Port Pipe Size	Port Location	Shape	Overall Ht.	For Use With	Temp. Range, ° F	Valve Type	Certification	Choose a Set Pressure, psi		Each







			Brass Body—Brass Seal

			1/2	Bottom	600	3/4	Side	90° Elbow	6 9/16"	Argon, Carbon Dioxide, Helium, Hydrogen, Methane, Nitrogen, Oxygen	-320 to 150	Pop Safety	ASME BPVC.VIII	20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, 300	8089K12	0000000


			3/4	Bottom	600	1	Side	90° Elbow	6 9/16"	Argon, Carbon Dioxide, Helium, Hydrogen, Methane, Nitrogen, Oxygen	-320 to 150	Pop Safety	ASME BPVC.VIII	20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, 300	8089K14	000000

High-Purity Tank-Mount Pressure-Regulating Valves for Fuel Gases

Single Stage

Two Stage

Designed to reduce contaminants in high-purity applications using hydrogen and methane gas, these valves have a stainless steel and brass body with a smooth finish to reduce dust collection and internal components designed to protect the seal and diaphragm from contamination. They’re often used in research sample systems, emission monitoring systems, and chromatography. Valves automatically reduce a high inlet pressure from compressed gas tanks to a lower, stable outlet pressure. All have Compressed Gas Association (CGA) numbered inlet fittings for secure connections to compressed gas tanks. Choose a valve with the same CGA number as your tank and other system components. Outlet fittings are Swagelok® for a leak-free seal around hard metal tubing in high-pressure lines. Also known as instrumentation fittings, Swagelok® fittings are compatible with Parker A-Lok, Gyrolok, Bilok, and Tylok fittings. Valves come with a gauge to monitor outlet pressure and a gauge to monitor inlet pressure from the tank.

Choose a valve with a maximum outlet pressure that’s approximately twice your application’s normal operating pressure. Your operating pressure should never exceed 75% of the valve’s maximum outlet pressure.

Single Stage—Single-stage valves reduce pressure in one step, which causes the outlet pressure to fluctuate slightly as you empty the tank. They’re best for applications where a constant outlet pressure isn’t critical.

Two Stage—Two-stage valves progressively reduce pressure over two steps for more consistent outlet pressure at all times. They’re often used in applications that require a constant outlet pressure regardless of the tank level.

	Inlet					Outlet
	CGA No.	Location	Thread Direction	Pressure Gauge Reading Range, psi	No. of Stages	For Tube OD	Location	Pressure Range, psi	Pressure Adjustment Method	For Use With	Temp. Range, ° F		Each
NGO Female Inlet × Swagelok® Female Outlet







				Brass Body/Stainless Steel Body—316 Stainless Steel Diaphragm and PTFE Seal with Relief Valve

				350	Side	Left Hand	0 to 4,000	Single	1/4"	Side	0 to 15	Knob	Hydrogen, Methane	-20 to 120	7951A17	0000000


				350	Side	Left Hand	0 to 4,000	Single	1/4"	Side	0 to 125	Knob	Hydrogen, Methane	-20 to 120	7951A19	000000
				350	Side	Left Hand	0 to 4,000	Two	1/4"	Side	0 to 15	Knob	Hydrogen, Methane	-20 to 120	7951A27	000000
				350	Side	Left Hand	0 to 4,000	Two	1/4"	Side	0 to 125	Knob	Hydrogen, Methane	-20 to 120	7951A29	000000
				350	Side	Left Hand	0 to 4,000	Two	1/4"	Side	0 to 500	Knob	Hydrogen, Methane	-20 to 120	7951A71	000000

Pressure-Regulating Valves for Fuel Gases

With T-Handle

Install these valves directly in gas distribution pipelines for acetylene, hydrogen, or propane. They automatically reduce a high inlet pressure to a lower, stable outlet pressure. Valves have two outlets to fit various pipe configurations and come with a plug to close the unused outlet. The gauge monitors outlet pressure. All valves are single stage and reduce pressure in one step, which causes the outlet pressure to fluctuate.

		Inlet			Outlet					Lg.
	For Use With	Pipe Size	Location	Max. Pressure, psi	Pipe Size	Location	Pressure Adjustment Method	Pressure Gauge Measurement Range, psi	Temp. Range, ° F	End-to-End	Port-to-Port		Each
NPT Female







				Brass Body—Stainless Steel Diaphragm and Neoprene Seal

				Hydrogen, Propane	1/4	Side	500	1/4	Bottom, Side	T-Handle	0 to 60	0 to 120	2.400"	1.01"	7864A11	0000000


				Hydrogen, Propane	1/4	Side	500	1/4	Bottom, Side	T-Handle	0 to 200	0 to 120	2.400"	1.01"	7864A12	000000

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.

Left-Hand Threads—UNF Male × UNF Female


Standard Flashback Arresters	High Flow Flashback Arresters	Quick Disconnect Flashback Arresters

Arresters with left-hand threads are for use with acetylene, hydrogen, and propane.

High Flow Flashback Arresters—High-flow arresters give you twice the airflow rate compared to standard flashback arresters when they’re used at the same inlet pressure. They are often used with larger torch tips.

Quick Disconnect Flashback Arresters—Quick-disconnect arresters have a fitting that connects and disconnects them from your torch, so you don't have to thread these arresters on and off with a wrench.

		Max. Pressure, psi
	Thread Size	Acetylene	Hydrogen	Propane	Material	Specs. Met		Each
Standard Flashback Arresters



		9/16"-18	15	50	50	Brass	EN 730, ISO 5175	78335A22	000000


		High Flow Flashback Arresters



				3/8"-24	15	50	50	Brass	EN 730, ISO 5175	7942A12	00000


				9/16"-18	15	50	50	Brass	EN 730, ISO 5175	78335A46	000000
				7/8"-14	15	50	50	Brass	EN 730, ISO 5175	78335A48	000000


				Quick Disconnect Flashback Arresters



						9/16"-18	15	50	72	Brass	EN 561, ISO 7289	78335A24	00000

Right-Hand and Left-Hand Threads—UNF Male × UNF Female

Standard

Flashback

Arresters

Arresters with right-hand threads are for use with oxygen.

Arresters with left-hand threads are for use with acetylene, hydrogen, and propane.

		Max. Pressure, psi
	Thread Size	Oxygen	Acetylene	Hydrogen	Propane	Material	Specs. Met		Pair
Standard Flashback Arresters



		9/16"-18	143	15	50	50	Brass	EN 730, ISO 5175	78335A41	0000000

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
Acetylene	Hydrogen	Propane	Thread Direction	Thread Size	Thread Type	Thread Direction	Thread Size	Thread Type	Material		Each
50	50	50	Left Hand	3/8"-24	UNF	Left Hand	3/8"-24	UNF	Brass	7957A8	000000
50	50	50	Left Hand	9/16"-18	UNF	Left Hand	9/16"-18	UNF	Brass	7957A2	00000

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.

Left-Hand Threads—UNF Male × UNF Female


Standard Flashback Arresters	High Flow Flashback Arresters	Quick Disconnect Flashback Arresters

Arresters with left-hand threads are for use with acetylene, hydrogen, and propane.

		Max. Pressure, psi
	Thread Size	Acetylene	Hydrogen	Propane	Material	Specs. Met		Each
Standard Flashback Arresters



		3/8"-24	15	50	50	Brass	EN 730, ISO 5175	7942A52	000000


		9/16"-18	15	50	50	Brass	EN 730, ISO 5175	78335A25	00000


		High Flow Flashback Arresters



				9/16"-18	15	50	50	Brass	EN 730, ISO 5175	78335A28	000000


				7/8"-14	15	50	50	Brass	EN 730, ISO 5175	78335A51	000000


				Quick Disconnect Flashback Arresters



						9/16"-18	15	50	50	Brass	EN 561, ISO 7289	78335A55	000000

Right-Hand and Left-Hand Threads—UNF Male × UNF Female

Standard

Flashback

Arresters

Arresters with right-hand threads are for use with oxygen.

Arresters with left-hand threads are for use with acetylene, hydrogen, and propane.

		Max. Pressure, psi
	Thread Size	Oxygen	Acetylene	Hydrogen	Propane	Material	Specs. Met		Pair
Standard Flashback Arresters



		9/16"-18	143	15	50	50	Brass	EN 730, ISO 5175	78335A43	0000000

Left-Hand Threads—NPT Female × NPT Female

Standard

Flashback

Arresters

Arresters with left-hand threads are for use with acetylene, hydrogen, and propane.

		Max. Pressure, psi
	Pipe Size	Acetylene	Hydrogen	Propane	Material	Specs. Met		Each
Standard Flashback Arresters



		1/4	15	50	50	Brass	EN 730, ISO 5175	78335A54	0000000

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
Acetylene	Hydrogen	Propane	Thread Direction	Thread Size	Thread Type	Thread Direction	Pipe Size	Thread Type	Material		Each
50	50	50	Right Hand	9/16"-18	UNF	Left Hand	1/4	NPT	Brass	7957A4	000000

Easy-Read Tank-Mount Pressure-Regulating Valves with Flowmeter for Inert Gas

Flowmeters let you see the gas flow rate from a distance. These valves automatically reduce a high inlet pressure from compressed gas tanks to a lower, stable outlet pressure. All have Compressed Gas Association (CGA) numbered inlet fittings for secure connections to compressed gas tanks. Choose a valve with the same CGA number as your tank and other system components. They have a gauge for monitoring inlet pressure from the tank.

For Helium and Hydrogen

Male Inlet × Female

Outlet With One

Flowmeter

1 Flowmeter—Valves with one flowmeter are for one piece of equipment on a tank. The flowmeter has a single scale.

	Inlet					Outlet					Material
	CGA No.	Location	Thread Direction	Pressure Gauge Reading Range, psi	No. of Stages	Thread Size	Location	Thread Direction	Flow Range	No. of Flowmeters	Body	Seal	Diaphragm		Each
UNF Female Outlet × NGO Male Inlet



		580	Side	Right Hand	0 to 4,000	Single	5/8"-18	Side	Right Hand	0 to 100 scfh (Helium), 0 to 140 scfh (Hydrogen)	1	Brass	PTFE	Neoprene	78595A499	0000000

Valve Union Fittings

		Each
Adapter	78595A49	000000

For Hydrogen

Female Inlet ×

Male Outlet With

One Flowmeter

1 Flowmeter—Valves with one flowmeter are for one piece of equipment on a tank. The flowmeter has a single scale.

	Inlet					Outlet					Material
	CGA No.	Location	Thread Direction	Pressure Gauge Reading Range, psi	No. of Stages	Thread Size	Location	Thread Direction	Flow Range	No. of Flowmeters	Body	Seal	Diaphragm		Each
UNF Male Outlet × NGO Female Inlet



		350	Side	Left Hand	0 to 3,000	Single	9/16"-18	Side	Left Hand	0 scfh to 40 scfh	1	Brass	PTFE	Neoprene	78595A498	0000000

Valve Union Fittings

		Each
Adapter	78595A49	000000

Tank-Mount Pressure-Regulating Valves for Fuel Gases

Attach these valves to acetylene, hydrogen, methane, propane, or propylene tanks to reduce a high inlet pressure to a lower, stable outlet pressure. They have Compressed Gas Association (CGA) numbered inlet fittings for secure connections to compressed gas tanks. Choose a valve with the same CGA number as your tank and other system components. Valves come with a gauge to monitor outlet pressure and a gauge to monitor inlet pressure from the tank.

Single Stage

Male Outlet × Female

Inlet Single-Stage Valve

With T-Handle

Single-stage valves reduce pressure in one step, which causes the outlet pressure to fluctuate slightly as you empty the tank. They’re best for applications where a constant outlet pressure isn’t critical.

Brass Body—Valves with a brass body have a longer service life than valves with a brass and steel body.

	Inlet				Outlet					Material
	CGA No.	Location	Thread Direction	Pressure Gauge Reading Range, psi	Thread Size	Location	Thread Direction	Pressure Range, psi	Pressure Adjustment Method	Body	Seal	Diaphragm	Temp. Range, ° F		Each
For Hydrogen







				UNF Male Outlet × NGO Female Inlet

				350	Side	Left Hand	0 to 4,000	9/16"-18	Side	Left Hand	0 to 125	T-Handle	Brass	PTFE	Rubber	-20 to 120	7897A5	0000000

Two Stage

Male Outlet × Female

Inlet Two-Stage Valve

With Knob

Two-stage valves progressively reduce pressure over two steps for more consistent outlet pressure at all times. They’re often used in applications that require a constant outlet pressure regardless of the tank level.

Brass Body—Valves with a brass body have a longer service life than valves with a brass and steel body.

Stainless Steel Diaphragm—Valves with a stainless steel diaphragm can withstand harsh environments.

	Inlet				Outlet					Material
	CGA No.	Location	Thread Direction	Pressure Gauge Reading Range, psi	Thread Size	Location	Thread Direction	Pressure Range, psi	Pressure Adjustment Method	Body	Seal	Diaphragm	Temp. Range, ° F		Each
For Hydrogen and Methane







				UNF Male Outlet × NGO Female Inlet

				350	Side	Left Hand	0 to 4,000	9/16"-18	Side	Left Hand	0 to 80	Knob	Brass	Neoprene	Stainless Steel	-20 to 120	7897A35	0000000