Boiler Gauges | McMaster-Carr

	Connection Location Connection Location

	Bottom		Center Back

	Pipe Size Pipe Size

	For Use With For Use With

Acetic Acid

Air

Alcohol-
Based
Solvents

	Measures Measures

Pressure

Temperature

	Scale Scale

	Scale Type Scale Type


Dual	Single

	Dial Diameter Dial Diameter

	Stem Length Stem Length

1 1/2"

	Maximum Process Temperature Maximum Process Temperature

140° F

150° F

320° F

	Gender Gender

Male

Female

	Case Material Case Material

Steel

Aluminum

	Lens Material Lens Material

Plastic

Glass

	Mount Type Mount Type

Bolt On

Screw

	Maximum Environment Temperature Maximum Environment Temperature

140° F

150° F

	Accuracy Grade Accuracy Grade

	Mounting Orientation Mounting Orientation

Any Angle

Upright

	Minimum Process Temperature Minimum Process Temperature

-40° F

70° F

	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

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

DFARS Specialty Metals
COTS-Exempt

	Connection Center-to-Center Connection Center-to-Center

	Material Material

	Number of Guard Rods Number of Guard Rods

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48 Products

About Pressure Gauges

About Pipe Size

Bottom Connection

Center Back Connection

Designed for use with boilers, these gauges have a dual scale that displays pressure in psi and feet of H₂O and displays temperature in °F/°C.

Painted Steel Case with Brass Connection—Dual Scale (psi/ft. of H₂O, Fahrenheit/Celsius)

For Use With: Steam and Water
Accuracy: ±2.5% Full Scale (Not Graded)

Available Pressure Ranges
Pressure Range		Graduation Marks		Numeric Increments
psi	ft. of H₂O	psi	ft. of H₂O	psi	ft. of H₂O
2 1/2" Dial Dia.
0 to 75	0 to 170	5	10	20	50
3 1/4" Dial Dia.
0 to 100	0 to 230	2	10	20	50
0 to 200	0 to 460	5	20	40	100

		Display Temp. Range
Dial Diameter	Pipe Size	°F	°C	Environment Temp. Range, °F	Process Temp. Range, °F	Case Color	Mounting Orientation	Stem Lg.	Shoulder Lg.		Each
Bottom Connection
NPT Male
3 1/4"	1/2	70° to 320°	20° to 160°	-40° to 140°	70° to 320°	Black	Any	2"	__	0000000	000000
Center Back Connection
NPT Male
2 1/2"	1/4	70° to 320°	20° to 160°	-40° to 140°	70° to 320°	Black	Any	1"	__	0000000	00000
2 1/2"	1/4	70° to 320°	20° to 160°	-40° to 140°	70° to 320°	Black	Any	1"	2"	0000000	00000
2 1/2"	1/4	70° to 320°	20° to 160°	-40° to 140°	70° to 320°	Black	Any	1 1/2"	2"	0000000	00000
3 1/4"	1/2	70° to 320°	20° to 160°	-40° to 140°	70° to 320°	Black	Any	2"	__	0000000	00000

Large-Dial High-Accuracy Pressure Gauges

Single Scale With Bottom Connection (Flange Mount)

Dual Scale With Bottom Connection

Bottom Connection (Flange Mount)

Read your pressure from a distance with these large-dial gauges. Use them with pumps, filters, regulators, and in process lines to measure and display pressure. They are suitable for critical processes that require high accuracy, such as hydraulic and laboratory applications. Mount gauges with the dial face upright.

Gauges with aluminum case have better corrosion resistance than gauges with steel case.

For technical drawings and 3-D models, click on a part number.

Painted Aluminum Case with Brass Connection—Single Scale (psi)

For Use With: Air, Water, and Hydraulic Fluid
Accuracy: ±1% Full Scale (Grade 1A)

Available Pressure Ranges
Pressure Range, psi	Graduation Marks, psi	Numeric Increments, psi
0 to 30	0.5	5
0 to 60	1	10
0 to 100	2	20
0 to 200	2	20
0 to 300	5	50
0 to 400	4	50
0 to 600	10	50

					Mounting		Bolt			Flange		Bottom Connection (Flange Mount)
Dial Diameter	Pipe Size	Environment Temp. Range, °F	Process Temp. Range, °F	Case Color	Orientation	Fasteners Included	Circle Dia.	Hole Dia.	No. of Holes	Location	OD		Each
NPT Male
8 1/2"	1/4	-40° to 150°	-40° to 150°	Black	Upright	No	9 5/8"	13/64"	3	Back	10 1/4"	0000000	0000000

Painted Steel Case with Brass Connection—Dual Scale (psi, bar)

For Use With: Air, Water, and Hydraulic Fluid
Accuracy: ±1% Full Scale (Grade 1A)

Available Pressure Ranges
Pressure Range		Graduation Marks		Numeric Increments
psi	bar	psi	bar	psi	bar
0 to 30	0 to 2.06	0.5	0.02	5	0.2
0 to 60	0 to 4.1	1	0.05	10	0.5
0 to 100	0 to 6.8	1	0.1	10	1
0 to 200	0 to 13.6	2	0.2	20	2
0 to 300	0 to 20.6	5	0.2	50	2
0 to 400	0 to 27.5	5	0.5	50	5
0 to 600	0 to 41	10	0.5	100	5

						Bottom Connection
Dial Diameter	Pipe Size	Environment Temp. Range, °F	Process Temp. Range, °F	Case Color	Mounting Orientation		Each
NPT Male
10"	1/2	-40° to 140°	-40° to 140°	Black	Upright	0000000	0000000

Level Indicators with Shut-Off Valve

Bronze

Brass

316 Stainless Steel With Ball-Valve-Style Drain

316 Stainless Steel

Shut-off valves stop flow so you can clean and replace gauge glass without removing these indicators from your equipment.

316 stainless steel indicators are more corrosion resistant than brass indicators.

Use indicators with stainless steel drain valve on expansion tanks.

Indicators with needle stem have a stem in the lower shut-off valve to clear the orifice as the valve closes.

Indicators with automatic shut-off will temporarily close if the gauge glass breaks. The valves must be closed manually for permanent shut-off.

For technical drawings and 3-D models, click on a part number.

Level Indicators
							Temp. Range, °F							Replacement Glass
Connection Ctr.-to-Ctr.	Overall Ht.	Window Ht.	Body Wd.	Drain Cock Dia.	Max. Pressure	Max. Steam Pressure	Min.	Max.	For Use With	No. of Guard Rods	Specifications Met		Each		Each
Bronze
3/8 NPT Male Thread with Needle Stem
11 1/4"	13 5/8"	7"	3 7/8"	1/4"	400 psi @ 70° F	200 psi @ 400° F	35°	400°	Water, Hydraulic Fluid, Salt Water, Steam	2	__	0000000	0000000	0000000	000000
1/2 NPT Male Thread with Needle Stem
13 1/4"	15 5/8"	9"	3 15/16"	1/4"	400 psi @ 70° F	200 psi @ 400° F	35°	400°	Water, Hydraulic Fluid, Salt Water, Steam	2	__	0000000	000000	0000000	00000
1/2 NPT Male Thread with Needle Stem and Automatic Shut-Off
13 1/4"	15 5/8"	9"	3 15/16"	1/4"	400 psi @ 70° F	200 psi @ 400° F	35°	400°	Water, Hydraulic Fluid, Salt Water, Steam	2	__	0000000	000000	0000000	00000
3/4 NPT Male Thread with Needle Stem
17 1/2"	20"	13"	4 3/16"	1/4"	370 psi @ 70° F	200 psi @ 400° F	35°	400°	Water, Hydraulic Fluid, Salt Water, Steam	2	__	0000000	000000	0000000	00000
3/4 NPT Male Thread with Needle Stem and Automatic Shut-Off
17 1/2"	20"	13"	4 3/16"	1/4"	370 psi @ 70° F	200 psi @ 400° F	35°	400°	Water, Hydraulic Fluid, Salt Water, Steam	2	__	0000000	000000	0000000	00000
Brass
1/2 NPT Male Thread with Needle Stem
14"	16 1/4"	9"	4 5/8"	1/4"	400 psi @ 70° F	200 psi @ 400° F	35°	400°	Water, Hydraulic Fluid, Salt Water, Steam	4	__	0000000	000000	0000000	00000
1/2 NPT Male Thread with Needle Stem and Automatic Shut-Off
14"	16 1/4"	9"	4 5/8"	1/4"	400 psi @ 70° F	200 psi @ 400° F	35°	400°	Water, Hydraulic Fluid, Salt Water, Steam	4	__	0000000	000000	0000000	00000
3/4 NPT Male Thread with Needle Stem
18"	20 1/4"	13"	4 5/16"	1/4"	370 psi @ 70° F	200 psi @ 400° F	35°	400°	Water, Hydraulic Fluid, Salt Water, Steam	4	__	0000000	000000	0000000	00000
3/4 NPT Male Thread with Needle Stem and Automatic Shut-Off
18"	20 1/4"	13"	4 5/16"	1/4"	370 psi @ 70° F	200 psi @ 400° F	35°	400°	Water, Hydraulic Fluid, Salt Water, Steam	4	__	0000000	000000	0000000	00000
316 Stainless Steel
1/2 NPT Male Thread with Stainless Steel Drain Valve
14"	15 3/4"	10 1/4"	3 15/16"	__	250 psi @ 400° F	250 psi @ 400° F	35°	400°	Water, Hydraulic Fluid, Steam	2	__	000000	000000	0000000	00000
1/2 NPT Male Thread with Ball-Valve-Style Drain and Automatic Shut-Off
14"	18 1/16"	10"	4 7/8"	__	410 psi @ 70° F	305 psi @ 400° F	35°	400°	Water, Hydraulic Fluid, Acetic Acid, Alcohol-Based Solvents, Ketone, Steam	4	ASME BPVC.I	0000000	000000	0000000	00000
3/4 NPT Male Thread with Stainless Steel Drain Valve
14"	15 3/4"	10 1/4"	3 7/8"	__	250 psi @ 400° F	250 psi @ 400° F	35°	400°	Water, Hydraulic Fluid, Steam	2	__	000000	000000	0000000	00000
3/4 NPT Male Thread with Ball-Valve-Style Drain and Automatic Shut-Off
18"	22 1/16"	12"	4 13/16"	__	370 psi @ 70° F	280 psi @ 400° F	35°	400°	Water, Hydraulic Fluid, Acetic Acid, Alcohol-Based Solvents, Ketone, Steam	4	ASME BPVC.I	0000000	00000000	0000000	00000

Heavy-Duty Level Indicators

Indicator with Reflex Glass

Shut-Off Valve

Reflex Glass

Gasket

Monitor liquid level in applications that have vibration, high pressures, and high temperatures. These indicators have steel chambers, glass windows, and seals made of fiber and SBR rubber to resist corrosion and withstand higher temperatures than other level indicators. Use them with a wide variety of liquids, such as petroleum, chemicals, and natural gas. All meet ASME BPVC.VIII.1 safety standards for pressure vessels, so they’re approved for use in low-pressure water and steam applications too. Their gauge is made of reflex glass, which shows the level of liquid behind the glass, but not the liquid’s color or any particulates in it. Also known as armored level gauges.

Add shut-off valves to stop flow with the turn of a wheel. They help you access indicators in order to clean or replace the glass or the entire indicator. These valves also stop flow automatically if the indicator glass breaks, preventing the loss of fluid. However, for permanent shut-off you must close them manually. Put one valve on top of your indicator and one on the bottom for a 90° connection between the indicator and your tank. To connect the female threads on your indicator to the female gauge threads on the shut-off valve, use a male pipe nipple (not included).

For technical drawings and 3-D models, click on a part number.

Indicators									Shut-Off Valves		Replacement Glass		Replacement Gaskets
Glass Size	Connection Center-to-Center	Overall Height	Window Height	Body Width	Maximum Pressure	Temperature Range, °F		Each		Each		Each		Each
Steel Indicator with Reflex Glass
1/2 NPT Female Thread
4	8 1/4"	16 1/2"	6 3/4"	3 3/4"	2,725 psi @ 70° F	-20° to 600°	00000000	0000000	00000000	0000000	00000000	000000	00000000	00000
5	9 3/8"	18 3/4"	7 7/8"	3 3/4"	2,630 psi @ 70° F	-20° to 600°	00000000	000000	00000000	000000	00000000	00000	00000000	0000
6	10 5/8"	10 5/8"	9 1/8"	3 3/4"	2,535 psi @ 70° F	-20° to 600°	00000000	000000	00000000	000000	00000000	00000	00000000	0000
7	11 3/4"	11 3/4"	10 1/4"	3 3/4"	2,440 psi @ 70° F	-20° to 600°	00000000	000000	00000000	000000	00000000	00000	00000000	0000
8	13 3/8"	13 3/8"	11 7/8"	3 3/4"	2,345 psi @ 70° F	-20° to 600°	00000000	000000	00000000	000000	00000000	00000	00000000	0000
9	14 1/8"	14 1/8"	12 5/8"	3 3/4"	2,250 psi @ 70° F	-20° to 600°	00000000	000000	00000000	000000	00000000	00000	00000000	0000

Gauge Glass for Heavy-Duty Level Indicators

Transparent Glass

Use this gauge glass with heavy duty level indicators.

Transparent glass helps you monitor the color of liquid and any particulates in it, in addition to the liquid’s level. Use two pieces of this glass in your indicator; the liquid flows between them, so you see straight through.

Use gaskets to seal the glass.

For technical drawings and 3-D models, click on a part number.

Gauge Glass
				Max. Pressure		Temp. Range, °F				Gaskets
Glass Size	Ht.	Wd.	Thick.	Liquid	Steam	Min.	Max.		Each		Each
Transparent Glass
4	7 1/2"	1 5/16"	11/16"	1,940 psi @ 100° F	1,620 psi @ 425° F	-20°	600°	000000000	0000000	00000000	00000
5	8 5/8"	1 5/16"	11/16"	1,750 psi @ 100° F	1,460 psi @ 425° F	-20°	600°	000000000	000000	00000000	0000
6	9 7/8"	1 5/16"	11/16"	1,565 psi @ 100° F	1,305 psi @ 425° F	-20°	600°	000000000	000000	00000000	0000
7	11"	1 5/16"	11/16"	1,375 psi @ 100° F	1,145 psi @ 425° F	-20°	600°	000000000	000000	00000000	0000
8	12 5/8"	1 5/16"	11/16"	1,190 psi @ 100° F	990 psi @ 425° F	-20°	600°	000000000	000000	00000000	0000
9	13 3/8"	1 5/16"	11/16"	1,000 psi @ 100° F	835 psi @ 425° F	-20°	600°	000000000	000000	00000000	0000

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About Pressure Gauges

About Pipe Size

Steam Pressure Gauges

Large-Dial High-Accuracy Pressure Gauges

Level Indicators with Shut-Off Valve

Heavy-Duty Level Indicators

Gauge Glass for Heavy-Duty Level Indicators