McMaster-Carr

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	Pipe Size Pipe Size

1/4

	Thread Type Thread Type

NPT

UNF

	For Use With For Use With	Show

Hydrogen

	For Use With For Use With	Hide

Warning: Products have one, but not necessarily all, of the selected characteristics.

Liquid Carbon Dioxide

Methyl Ethyl Ketone
(MEK)

	Connection Type Connection Type


Pipe	Hose

	Inlet CGA Number Inlet CGA Number

CGA 350

	System of Measurement System of Measurement

Inch

	Thread Size Thread Size

3/8"-24

9/16"-18

	Thread Direction Thread Direction

Right Hand

Left Hand

	Gender Gender

Female

Male

	Body Material Body Material

Brass

Brass/Stainless Steel

	Material Material

Brass

	Component Component

Check Valve

Flashback Arrester

	Maximum Pressure for Acetylene Maximum Pressure for Acetylene

15 psi

50 psi

	Connection Style Connection Style

	Threaded

	Specifications Met Specifications Met

European Safety
Specification EN730

ISO

	Stage Stage

Single

Two

	Inlet Thread Type Inlet Thread Type

National Gas Outlet (NGO)

NPT

	Outlet Connection Type Outlet Connection Type


Pipe	Tube

	Maximum Inlet Pressure Maximum Inlet Pressure

500 to 999 psi

1,000 to 3,999 psi

	Maximum Outlet Pressure Gauge Maximum Outlet Pressure Gauge

30 psi

60 psi

200 psi

	Outlet Gender Outlet Gender

Female

Male

	Outlet Pressure Outlet Pressure

0-15 psi

0-60 psi

0-125 psi

0-200 psi

2-40 psi

	Inlet Connection Type Inlet Connection Type


Pipe	Hose

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15 Products

About Gas Regulators

Single Stage

Two Stage

For Use With: Hydrogen, Methane
Temperature Range: -20° to 120° F

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 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 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 Number	Location	Thread Direction	Pressure Gauge Range, psi	Stage	For Tube OD	Location	Pressure Range, psi	Pressure Adjustment Method		Each
Swagelok® Female Outlet × NGO Female Inlet
Brass/Stainless Steel Body—316 Stainless Steel Diaphragm and PTFE Seal with Relief Valve
CGA 350	Side	Left Hand	0 to 4,000	Single	1/4"	Side	0 to 15	Knob	0000000	0000000
CGA 350	Side	Left Hand	0 to 4,000	Single	1/4"	Side	0 to 125	Knob	0000000	000000
CGA 350	Side	Left Hand	0 to 4,000	Two	1/4"	Side	0 to 15	Knob	0000000	000000
CGA 350	Side	Left Hand	0 to 4,000	Two	1/4"	Side	0 to 125	Knob	0000000	000000

Tank-Mount Pressure-Regulating Valves for Fuel Gases

For Use With: See Table
Temperature Range: -20° to 120° F

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.

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

Single-Stage Valves

Male Outlet × Female Inlet Single-Stage Valve With T-Handle

Inlet				Outlet					Material
CGA Number	Location	Thread Direction	Pressure Gauge Range, psi	Thread Size	Location	Thread Direction	Pressure Range, psi	Pressure Adjustment Method	Body	Seal	Diaphragm		Each
For Use With Hydrogen
UNF Male Outlet × NGO Female Inlet
CGA 350	Side	Left Hand	0 to 4,000	9/16"-18	Side	Left Hand	0 to 125	T-Handle	Brass	PTFE	Rubber	000000	0000000

Two-Stage Valves

Male Outlet × Female Inlet Two-Stage Valve With Knob

Inlet				Outlet					Material
CGA Number	Location	Thread Direction	Pressure Gauge Range, psi	Thread Size	Location	Thread Direction	Pressure Range, psi	Pressure Adjustment Method	Body	Seal	Diaphragm		Each
For Use With Hydrogen and Methane
UNF Male Outlet × NGO Female Inlet
CGA 350	Side	Left Hand	0 to 4,000	9/16"-18	Side	Left Hand	2 to 40	Knob	Brass	Neoprene	Rubber	0000000	0000000

Pressure-Regulating Valves for Fuel Gases

With T-Handle

For Use With: See Table
Temperature Range: See Table

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
For Use With	Pipe Size	Location	Max. Pressure, psi	Pipe Size	Location	Pressure Adjustment Method	Pressure Gauge Range, psi	Temperature Range, ° F	End-to-End Lg.	Port-to-Port Lg.		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°	2.40"	1.01"	0000000	000000
Hydrogen, Propane	1/4	Side	500	1/4	Bottom, Side	T-Handle	0 to 200	0° to 120°	2.40"	1.01"	0000000	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
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	000000	000000
50	50	50	Left Hand	9/16"-18	UNF	Left Hand	9/16"-18	UNF	Brass	000000	0000

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	000000	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.

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

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.