20 psi Pressure Gauges | McMaster-Carr

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For Use With

System of Measurement

Outlet Pressure

Pipe Size

Inlet Pipe Size

Material

Minimum Pressure

Maximum Pressure

1,000 psi to 1,999.9 psi

2,000 psi to 9,999.9 psi

10,000 psi to 19,999.9 psi

20,000 psi or greater

Less than 10,000 kPa

10,000 kPa to 19,999 kPa

20,000 kPa to 29,999 kPa

30,000 kPa to 99,999 kPa

100,000 kPa or greater

Measurement Unit

Pounds per Square Inch

Fitting Connection

Body Material

Maximum Inlet Pressure

Less than 250 psi

250 psi to 499 psi

500 psi to 999 psi

Maximum Pressure Regulation

Outlet Pipe Size

Thread Type

Inlet Thread Type

Outlet Thread Type

Valve Function

Display Type

Maximum Temperature

Measures

Differential Pressure

Differential Vacuum

REACH

Compliant

Not Compliant

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

Yes

RoHS

Compliant

Compliant with Exemptions

Not Compliant

DFARS Specialty Metals

Exempt

Export Control Classification Number (ECCN)

60 Products

Low-Pressure Differential Gauges with Color Indicator

A band of green, yellow, and red provides a clear indication of changes in differential pressure. Gauges are commonly used to indicate clogged filters.

Glass-Filled Nylon Case with Anodized Aluminum Connections (Pounds per Square Inch)

Image of Product. Front orientation. Differential Pressure Gauges. Low-Pressure Differential Gauges with Color Indicator.

	Pressure Range, psi
	Green Band	Yellow Band	Red Band	Max. Pressure, psi	Environment Temp. Range, ° F	Process Temp. Range, ° F	Ht.	Wd.	Dp.	Case Color	For Use With	Accuracy		Each
1/4 NPT Female Threaded Pipe Connection



		0 to 13	13 to 20	20 to 30	300	-40 to 200	-40 to 200	3 1/4"	3 1/4"	1 1/2"	Black	Air, Water, Hydraulic Fluid, Carbon Dioxide, Nitrogen, Hydrogen, Argon, Acetylene	±5%	2238K27	0000000

Low-Pressure-Regulating Valves for Water

Designed for excellent performance at low pressures, these valves respond to even the slightest inlet pressure changes to maintain a lower, stable outlet pressure. Adjust the outlet pressure within the range. Valves have an internal strainer to trap debris.

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







				Brass Body—Buna-N-Coated Nylon Diaphragm and 303 Stainless Steel Seal with Internal Strainer

				1/4	Side	300	1/4	Side	T-Handle	4 1/4"	Water	0 to 120	0 to 20	3878T41	0000000

Differential Pressure and Vacuum Gauges with Digital Display

Gauges have a four-digit LCD display for easy reading of measurements. Commonly used to indicate clogged filters, these gauges display the difference between two pressure or vacuum measurements. They are also known as compound gauges.

Aluminum Case with Brass Connection—(psi, kPa, in. of H₂O, in. of Hg, mbar)

Image of Product. Front orientation. Differential Pressure and Vacuum Gauges. Differential Pressure and Vacuum Gauges with Digital Display .

	Vacuum Range, in. Hg	Pressure Resolution, in. H₂O	Max. Pressure	For Tube ID	Environment Temp. Range, ° F	Process Temp. Range, ° F	Digit Ht.	Batteries Included	Features	For Use With	Accuracy		Each
Barbed Fitting Connection



	0 psi to 20 psi 0 psi to 60 psi 0 kPa to 137.9 kPa 0 in. H₂O to 553 in. H₂O 0 mbar to 1,379 mbar	0 to 40.72	0.01	20 psi; 60 psi; 137.9 kPa; 553 in. H₂O; 1,379 mbar	1/8" to 3/16"	35 to 100	0 to 140	3/8"	Yes	40-Reading Memory, Overpressure Alarm	Air	±0.5% Full-Scale Accuracy (Not Rated)	4125K46	0000000


	Barbed Fitting Connection with Calibration Certificate Traceable to NIST



			0 psi to 20 psi 0 psi to 60 psi 0 kPa to 137.9 kPa 0 in. H₂O to 553 in. H₂O 0 mbar to 1,379 mbar	0 to 40.72	0.01	20 psi; 60 psi; 137.9 kPa; 553 in. H₂O; 1,379 mbar	1/8" to 3/16"	35 to 100	0 to 140	3/8"	Yes	40-Reading Memory, Overpressure Alarm	Air	±0.5% Full-Scale Accuracy (Not Rated)	4125K66	000000

High-Accuracy Pressure-Regulating Valves for Steam

Control steam line pressure with ±1 psi accuracy. These valves automatically reduce a high, variable inlet pressure to a lower, stable outlet pressure. Adjust the outlet pressure within the range. Valves have a cast iron body that absorbs vibration from pressure changes to reduce wear and noise in your pipeline. They meet ANSI/FCI 70-2 Class IV for tight shut-off (max. leakage rate of 0.01%). Install _1/4 NPT male pipe (not included) between the control valve and your downstream steam line.

Repair Kits—Repair kits (sold separately) include replacement seals, diaphragm, spring, and spring assembly.

	Valves												Repair Kits
	Inlet			Outlet
	Pipe Size	Location	Max. Pressure, psi	Pipe Size	Location	Pressure Adjustment Method	For Use With	Temp. Range, ° F	Specs. Met	Outlet Pressure, psi		Each		Each
NPT Female







				Cast Iron Body—301 Stainless Steel Diaphragm and 420 Stainless Steel Seal

				1/2	Side	250	1/2	Side	Screw	Steam	40 to 450	ANSI/FCI 70-2 Class IV	3 to 20	9792K19	000000000	9792K32	0000000


				3/4	Side	250	3/4	Side	Screw	Steam	40 to 450	ANSI/FCI 70-2 Class IV	3 to 20	9792K21	00000000	9792K33	000000
				1	Side	250	1	Side	Screw	Steam	40 to 450	ANSI/FCI 70-2 Class IV	3 to 20	9792K23	00000000	9792K34	000000
				1 1/4	Side	250	1 1/4	Side	Screw	Steam	40 to 450	ANSI/FCI 70-2 Class IV	3 to 20	9792K25	00000000	9792K35	000000
				1 1/2	Side	250	1 1/2	Side	Screw	Steam	40 to 450	ANSI/FCI 70-2 Class IV	3 to 20	9792K27	00000000	9792K36	000000
				2	Side	250	2	Side	Screw	Steam	40 to 450	ANSI/FCI 70-2 Class IV	3 to 20	9792K29	00000000	9792K37	00000000

High-Pressure Differential Gauges

These gauges are able to withstand line pressures up to 3,000 pounds per square inch. They are commonly used to measure pressure differences in pumps and filters.

Aluminum Case with Aluminum Connections—Single Scale (Pounds per Square Inch)

Image of Product. Front orientation. Differential Pressure Gauges. High-Pressure Differential Gauges.

	Max. Pressure, psi	Environment Temp. Range, ° F	Process Temp. Range, ° F	For Use With	Accuracy	Pressure, psi	Graduations, psi	Pressure Numeric Increments, psi		Each
1/4 NPT Female Threaded Pipe Connection



	2 1/2"	3,000	0 to 150	0 to 200	Water, Hydraulic Fluid, Gasoline	±2%	0 to 20	1	5	4107K117	0000000


	4 1/2"	3,000	0 to 150	0 to 200	Water, Hydraulic Fluid, Gasoline	±2%	0 to 20	1	5	4107K513	000000

316 Stainless Steel Case with 316 Stainless Steel Connections—Single Scale (Pounds per Square Inch)

Gauges with 316 stainless steel case are more corrosion resistant than gauges with an aluminum case.

	Max. Pressure, psi	Environment Temp. Range, ° F	Process Temp. Range, ° F	For Use With	Accuracy	Pressure, psi	Graduations, psi	Pressure Numeric Increments, psi		Each
1/4 NPT Female Threaded Pipe Connection



	2 1/2"	3,000	0 to 150	0 to 200	Water, Hydraulic Fluid, Gasoline	±2%	0 to 20	1	5	4232K113	0000000


	4 1/2"	3,000	0 to 150	0 to 200	Water, Hydraulic Fluid, Gasoline	±2%	0 to 20	1	5	4232K513	000000

Vibration-Damping Pressure-Regulating Valves for Water, Oil, Air, and Inert Gas

A cast iron body absorbs vibration from pressure changes to reduce wear and noise in your pipeline. These valves automatically reduce a high, variable inlet pressure to a lower, stable outlet pressure. Adjust the outlet pressure within the range.

Internal Strainer—Internal strainers trap debris.

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







				Cast Iron Body—Buna-N Diaphragm and Seal with Internal Strainer

				3/4	Side	200	3/4	Side	Screw	5 1/8"	Water, Oil, Air, Inert Gas	32 to 180	2 to 20	4674K44	0000000


				1	Side	200	1	Side	Screw	5 7/8"	Water, Oil, Air, Inert Gas	32 to 180	2 to 20	4674K45	000000
				2	Side	200	2	Side	Screw	9 1/4"	Water, Oil, Air, Inert Gas	32 to 180	2 to 20	4674K48	00000000

Manifold-Mount Compressed Air Regulators

Multiple Regulators

Shown Installed

(Manifold Sold

Separately)

Mount these miniature regulators on a manifold (sold separately) to create a regulating manifold. Each regulator can be set to a different output pressure, so you can power multiple tools or machines with a single air supply. All are relieving regulators, so they exhaust when the downstream pressure exceeds the set pressure. Install them in your air line after filters.

NPT Male Inlet × UNF Threaded Female Outlet

Panel-Mount Nut—Regulators with a panel-mount nut can be installed through a hole in a panel or enclosure. They let you hide your air lines without losing access to the control knob.

Regulators														4-Outlet Manifolds		6-Outlet Manifolds		10-Outlet Manifolds
						Overall
Inlet Pipe Size	Outlet Thread Size	Max. Flow Rate @ Pressure	Max. Pressure, psi	Housing Material	Gauge Included	Wd.	Ht.	Max. Temp., ° F	Includes	Regulating Accuracy	Pressure Regulation, psi		Each		Each		Each		Each
1/8	10-32	5 scfm @ 100 psi	250	Brass	No	3/4"	2 3/4"	150	Panel-Mount Nut	±10%	0 to 20	41795K4	000000	5469K121	000000	5469K151	000000	5469K191	000000

Tire Gauges with Indicator Bar

A bar slides out of the top of these gauges to display pressure reading.

1 Angled Head

Stainless Steel—Stainless steel gauges are more corrosion resistant than steel and brass gauges.

	Pressure Numeric Increments, psi	Accuracy	Overall Lg.	Indicator Bar Material	Features		Each
Nickel-Plated Brass



	2 psi to 20 psi, 20 kPa to 140 kPa	1	±1 psi	6"	Plastic	Pocket Clip	6637A21	000000


	Stainless Steel



			2 psi to 20 psi	1	±2 psi	5 3/4"	Plastic	Pocket Clip	6637A107	0000

High-Temperature Pressure-Regulating Valves for Water, Oil, Air, and Inert Gas

Rated for more than double the temperature of standard pressure-regulating valves, these can withstand temperatures up to 550° F. They automatically reduce a high, variable inlet pressure to a lower, stable outlet pressure. Adjust the outlet pressure within the range. Valves meet ANSI/FCI 70-2 Class IV for tight shut-off (max. leakage rate of 0.01%).

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







				Steel Body—316 Stainless Steel Diaphragm and 303 Stainless Steel Seal

				1	Side	300	1	Side	Screw	4 3/16"	Water, Oil, Air, Inert Gas	32 to 550	ANSI/FCI 70-2 Class IV	5 to 20	46395K25	000000000


				1 1/2	Side	300	1 1/2	Side	Screw	4 13/16"	Water, Oil, Air, Inert Gas	32 to 550	ANSI/FCI 70-2 Class IV	5 to 20	46395K27	00000000
				2	Side	300	2	Side	Screw	5 1/2"	Water, Oil, Air, Inert Gas	32 to 550	ANSI/FCI 70-2 Class IV	5 to 20	46395K29	00000000

Long-Life Pressure-Regulating Valves for Steam

For a longer service life than cast iron valves, these have a durable bronze body. All automatically reduce a high, variable inlet pressure to a lower, stable outlet pressure. Adjust the outlet pressure within the range. Valves have an internal strainer to trap debris.

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







				Bronze Body—Bronze Diaphragm and PTFE Seal with Internal Strainer

				3/4	Side	250	3/4	Side	Screw	5 1/8"	Steam	-20 to 400	2 to 20	47345K34	0000000


				1	Side	250	1	Side	Screw	5 7/8"	Steam	-20 to 400	2 to 20	47345K35	000000
				2	Side	250	2	Side	Screw	9 1/4"	Steam	-20 to 400	2 to 20	47345K38	00000000

Corrosion-Resistant Pressure-Regulating Valves for Water, Oil, Air, and Inert Gas

Image of Product. Front orientation. Pressure-Regulating Valves. Corrosion-Resistant Pressure-Regulating Valves for Water, Oil, Air, and Inert Gas.

Often used in wet conditions and harsh environments, these valves have a 316 stainless steel body for excellent corrosion resistance. They automatically reduce a high, variable inlet pressure to a lower, stable outlet pressure. Adjust the outlet pressure within the range.

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







				316 Stainless Steel Body—Buna-N Diaphragm and Seal

				3/4	Side	720	3/4	Side	Screw	5 1/8"	Water, Oil, Air, Inert Gas	32 to 200	2 to 20	8099K21	000000000


				1	Side	720	1	Side	Screw	5 7/8"	Water, Oil, Air, Inert Gas	32 to 200	2 to 20	8099K31	00000000

Pressure Recording Film

Create an instant, permanent image of pressure distribution and magnitude. These sheets of film help you identify uneven pressure that can lead to leaks and stress fractures. Use them between any two surfaces that touch each other, such as bolted joints, welding fixtures, and jigs. Tiny capsules within the film burst at specific pressure levels, causing the film to change color. This produces an instant map of pressure variation, similar to a heat map. For a custom size, cut the film with scissors.

Pressure Film


Impression Record Before Analysis

Film that includes two sheets must be used together.

	Includes	Accuracy		Each
11" × 17"







	0.02" Thick

	2 to 20	Grayscale	0 to 150	Two 0.01" Thick Sheets	Not Rated	3145K22	000000

Long-Life Pressure-Regulating Valves for Water, Oil, Air, and Inert Gas

For a longer service life than brass and cast iron valves, these have a durable bronze body. They automatically reduce a high, variable inlet pressure to a lower, stable outlet pressure. Adjust the outlet pressure within the range. All valves have an internal strainer to trap debris.

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







				Bronze Body—Buna-N Diaphragm and Seal with Internal Strainer

				3/4	Side	400	3/4	Side	Screw	5 1/8"	Water, Oil, Air, Inert Gas	32 to 180	2 to 20	47345K14	0000000


				1	Side	400	1	Side	Screw	5 7/8"	Water, Oil, Air, Inert Gas	32 to 180	2 to 20	47345K15	000000
				2	Side	400	2	Side	Screw	9 1/4"	Water, Oil, Air, Inert Gas	32 to 180	2 to 20	47345K18	00000000

Pressure-Regulating Valves for Steam

Automatically reduce a high, variable inlet pressure in your steam system to a lower, stable outlet pressure. Adjust the outlet pressure within the range. These valves have a cast iron body that absorbs vibration from pressure changes to reduce wear and noise in your pipeline.

Internal Strainer—Internal strainers trap debris.

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







				Cast Iron Body—Bronze Diaphragm and PTFE Seal with Internal Strainer

				3/4	Side	150	3/4	Side	Screw	5 1/8"	Steam	-20 to 400	2 to 20	4674K64	0000000	4674K92	0000000


				1	Side	150	1	Side	Screw	5 7/8"	Steam	-20 to 400	2 to 20	4674K65	000000	4674K93	000000
				2	Side	150	2	Side	Screw	9 1/4"	Steam	-20 to 400	2 to 20	4674K68	00000000	4674K95	000000

Compact Compressed Air Regulators

A lower profile than our other compressed air regulators makes these regulators a better fit in tight spots. Use them to adjust and maintain the pressure of your compressed air. Install them in your air line after filters.

Relieving with Gauge Not Included

Relieving regulators exhaust when the downstream pressure exceeds the set pressure.

Mounting Brackets—Mounting brackets (sold separately) allow you to attach the regulator to a wall or equipment.

	Regulators													Mounting Brackets
	Pipe Size						Overall
	Inlet	Outlet	Max. Flow Rate @ Pressure	Max. Pressure, psi	Housing Material	No. of Gauge Ports	Wd.	Ht.	Max. Temp., ° F	Regulating Accuracy	Pressure Regulation, psi		Each		Each
NPT Female Inlet × NPT Female Outlet



		1/8	1/8	25 scfm @ 100 psi	250	Nylon	2	1 1/2"	2 3/4"	120	±3 psi	3 to 20	6746K28	000000	6746K83	00000


		1/4	1/4	25 scfm @ 100 psi	250	Nylon	2	1 1/2"	2 3/4"	120	±3 psi	3 to 20	6746K29	00000	6746K83	0000

Relieving with Gauge Included

Relieving regulators exhaust when the downstream pressure exceeds the set pressure.

Mounting Brackets—Mounting brackets (sold separately) allow you to attach the regulator to a wall or equipment.

	Regulators												Mounting Brackets
	Pipe Size					Overall
	Inlet	Outlet	Max. Flow Rate @ Pressure	Max. Pressure, psi	Housing Material	Wd.	Ht.	Max. Temp., ° F	Regulating Accuracy	Pressure Regulation, psi		Each		Each
NPT Female Inlet × NPT Female Outlet



		1/8	1/8	25 scfm @ 100 psi	250	Nylon	1 1/2"	2 3/4"	120	±3 psi	3 to 20	6746K38	000000	6746K83	00000


		1/4	1/4	25 scfm @ 100 psi	250	Nylon	1 1/2"	2 3/4"	120	±3 psi	3 to 20	6746K39	00000	6746K83	0000

Differential Pressure Transmitters for Liquids

Used with pumps, cooling systems, and other liquid applications, these transmitters remotely measure the difference in pressure between two inputs. They are also known as transducers. These transmitters convert differential pressure to an electrical signal that can be interpreted by receiving devices, such as remote displays, programmable logic controllers, and motor speed controls to monitor pressure or control equipment. You’ll often see them used to indicate a filter is clogged.

For your receiving device to interpret the signal from the transmitter, you will need to calibrate it for the transmitter's differential pressure range and output signal. Transmitters will only provide accurate readings within the rated pressure range. Connect them using two wires. The same wire is used to send a signal to the receiver and to power the transmitter. Current doesn’t lose signal over long distances and isn’t affected by electrical interference from other devices.

Steel Housing

Image of Product. Front orientation. Contains Annotated. Differential Pressure Transmitters. Differential Pressure Transmitters for Liquids, Steel Housing.

IP56 Enclosure Rating—IP56 rated transmitters protect against some dust and washdowns.

NEMA 4 Enclosure Rating—NEMA 4 rated transmitters protect against weather and washdowns.

							Mounting Holes							Connection
	Pressure Differential	Max. Input Pressure, psi	Input Voltage, V DC	Pipe Size	For No. of Wires	Mounting Hardware Included	Dia.	No. of	Ht.	Wd.	Enclosure Rating	For Use With	Accuracy	Pipe	Fitting	Material	Temp. Range, ° F		Each
4 to 20 mA Output Signal—Screw Terminals



		0 in. H₂O to 1 in. H₂O	20	18 to 30	1/8	2	No	7/32"	4	3 5/16"	2 15/16"	IP56, NEMA 4	Hydraulic Fluid, Water	±1%	NPT Female	Threaded	Brass	32 to 122	5842N11	000000000


		0 in. H₂O to 3 in. H₂O	20	18 to 30	1/8	2	No	7/32"	4	3 5/16"	2 15/16"	IP56, NEMA 4	Hydraulic Fluid, Water	±1%	NPT Female	Threaded	Brass	32 to 122	5842N12	000000
		0 in. H₂O to 5 in. H₂O	20	18 to 30	1/8	2	No	7/32"	4	3 5/16"	2 15/16"	IP56, NEMA 4	Hydraulic Fluid, Water	±1%	NPT Female	Threaded	Brass	32 to 122	5842N13	000000
		0 in. H₂O to 10 in. H₂O	20	18 to 30	1/8	2	No	7/32"	4	3 5/16"	2 15/16"	IP56, NEMA 4	Hydraulic Fluid, Water	±1%	NPT Female	Threaded	Brass	32 to 122	5842N14	000000
		0 in. H₂O to 25 in. H₂O	20	18 to 30	1/8	2	No	7/32"	4	3 5/16"	2 15/16"	IP56, NEMA 4	Hydraulic Fluid, Water	±1%	NPT Female	Threaded	Brass	32 to 122	5842N15	000000
		0 psi to 1 psi	20	18 to 30	1/8	2	No	7/32"	4	3 5/16"	2 15/16"	IP56, NEMA 4	Hydraulic Fluid, Water	±1%	NPT Female	Threaded	Brass	32 to 122	5842N16	000000

Corrosion-Resistant Pressure-Regulating Valves for Steam

Regulate steam pressure in wet environments and harsh conditions with these valves that have a 316 stainless steel body for exceptional corrosion resistance. They automatically reduce a high, variable inlet pressure to a lower, stable outlet pressure. Adjust the outlet pressure within the range.

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







				316 Stainless Steel Body—316 Stainless Steel Diaphragm and PTFE Seal

				3/4	Side	400	3/4	Side	Screw	5 1/8"	Steam	-40 to 450	2 to 20	8099K51	000000000


				1	Side	400	1	Side	Screw	5 7/8"	Steam	-40 to 450	2 to 20	8099K61	00000000