Boiler Safety Valves | McMaster-Carr

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Compliant with Exemptions

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

Yes

Export Control Classification Number (ECCN)

EAR99

DFARS Specialty Metals

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64 Products

ASME-Code Fast-Acting Pressure-Relief Valves for Steam

These valves meet ASME Code Section I for use with steam power boilers requiring pressure relief above 15 psi. They spring fully open at the set pressure and remain open until the system pressure is restored below the set pressure. For remote discharge, attach a drain line to the threaded relief port. Valves have a durable bronze body for a long service life.

NPT Male Inlet and NPT Female Relief Port


Valve With Test Lever	Valve With Swivel Test Lever

EPM Rubber Seal—EPM rubber seals provide better leak protection than brass seals.

Swivel—Swivel test levers rotate 360° around the valve for use in areas with limited clearance.

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







			Bronze Body—Brass Seal

			1/2	Bottom	250	3/4	Side	90° Elbow	6 1/2"	Steam	-60 to 400	Lever	—	Pop Safety	ASME BPVC.I	15 , 20 , 25 , 30 , 35 , 40 , 45 , 50 , 55 , 60 , 65 , 70 , 75 , 80 , 85 , 90 , 95 , 100 , 125 , 150 , 175 , 200 , 225 , 250	4700K23	0000000


			1/2	Bottom	250	3/4	Side	90° Elbow	7 5/16"	Steam	-60 to 400	Lever	Swivel	Pop Safety	ASME BPVC.I	15 , 20 , 25 , 30 , 35 , 40 , 45 , 50 , 55 , 60 , 65 , 70 , 75 , 80 , 85 , 90 , 95 , 100 , 125 , 150 , 175 , 200 , 225 , 250	4755K11	000000
			3/4	Bottom	250	3/4	Side	90° Elbow	7 5/16"	Steam	-60 to 400	Lever	Swivel	Pop Safety	ASME BPVC.I	15 , 20 , 25 , 30 , 35 , 40 , 45 , 50 , 55 , 60 , 65 , 70 , 75 , 80 , 85 , 90 , 95 , 100 , 125 , 150 , 175 , 200 , 225 , 250	4755K12	000000
			3/4	Bottom	250	1	Side	90° Elbow	7 1/2"	Steam	-60 to 400	Lever	—	Pop Safety	ASME BPVC.I	15 , 20 , 25 , 30 , 35 , 40 , 45 , 50 , 55 , 60 , 65 , 70 , 75 , 80 , 85 , 90 , 95 , 100 , 125 , 150 , 175 , 200 , 225 , 250	4700K24	000000
			1	Bottom	250	1	Side	90° Elbow	7 5/8"	Steam	-60 to 400	Lever	Swivel	Pop Safety	ASME BPVC.I	15 , 20 , 25 , 30 , 35 , 40 , 45 , 50 , 55 , 60 , 65 , 70 , 75 , 80 , 85 , 90 , 95 , 100 , 125 , 150 , 175 , 200 , 225 , 250	4755K13	000000
			1	Bottom	250	1 1/4	Side	90° Elbow	8 1/2"	Steam	-60 to 400	Lever	—	Pop Safety	ASME BPVC.I	15 , 20 , 25 , 30 , 35 , 40 , 45 , 50 , 55 , 60 , 65 , 70 , 75 , 80 , 85 , 90 , 95 , 100 , 125 , 150 , 175 , 200 , 225 , 250	4700K25	000000
			1 1/4	Bottom	250	1 1/2	Side	90° Elbow	9 5/8"	Steam	-60 to 400	Lever	—	Pop Safety	ASME BPVC.I	15 , 20 , 25 , 30 , 35 , 40 , 45 , 50 , 55 , 60 , 65 , 70 , 75 , 80 , 85 , 90 , 95 , 100 , 125 , 150 , 175 , 200 , 225 , 250	4700K26	000000
			1 1/2	Bottom	250	1 1/2	Side	90° Elbow	9 5/8"	Steam	-60 to 400	Lever	Swivel	Pop Safety	ASME BPVC.I	15 , 20 , 25 , 30 , 35 , 40 , 45 , 50 , 55 , 60 , 65 , 70 , 75 , 80 , 85 , 90 , 95 , 100 , 125 , 150 , 175 , 200 , 225 , 250	4755K15	000000
			1 1/2	Bottom	250	2	Side	90° Elbow	10 5/8"	Steam	-60 to 400	Lever	—	Pop Safety	ASME BPVC.I	15 , 20 , 25 , 30 , 35 , 40 , 45 , 50 , 55 , 60 , 65 , 70 , 75 , 80 , 85 , 90 , 95 , 100 , 125 , 150 , 175 , 200 , 225 , 250	4700K27	000000
			2	Bottom	250	2 1/2	Side	90° Elbow	13 5/8"	Steam	-60 to 400	Lever	—	Pop Safety	ASME BPVC.I	15 , 20 , 25 , 30 , 35 , 40 , 45 , 50 , 55 , 60 , 65 , 70 , 75 , 80 , 85 , 90 , 95 , 100 , 125 , 150 , 175 , 200 , 225 , 250	4700K28	000000




					Bronze Body—EPM Rubber Seal

					1/2	Bottom	250	3/4	Side	90° Elbow	6 1/2"	Steam	-60 to 400	Lever	—	Pop Safety	ASME BPVC.I	15 , 20 , 25 , 30 , 35 , 40 , 45 , 50 , 55 , 60 , 65 , 70 , 75 , 80 , 85 , 90 , 95 , 100 , 125 , 150 , 175 , 200 , 225 , 250	6187T17	000000


					3/4	Bottom	250	1	Side	90° Elbow	7 1/2"	Steam	-60 to 400	Lever	—	Pop Safety	ASME BPVC.I	15 , 20 , 25 , 30 , 35 , 40 , 45 , 50 , 55 , 60 , 65 , 70 , 75 , 80 , 85 , 90 , 95 , 100 , 125 , 150 , 175 , 200 , 225 , 250	6187T18	000000
					1	Bottom	250	1 1/4	Side	90° Elbow	8 1/2"	Steam	-60 to 400	Lever	—	Pop Safety	ASME BPVC.I	15 , 20 , 25 , 30 , 35 , 40 , 45 , 50 , 55 , 60 , 65 , 70 , 75 , 80 , 85 , 90 , 95 , 100 , 125 , 150 , 175 , 200 , 225 , 250	6187T19	000000

ASME-Code Fast-Acting Pressure-Relief Valves for Low-Pressure Steam

For use with low-pressure steam-heating boilers requiring pressure relief at 15 psi, these valves meet ASME Code Section IV. All spring fully open at the set pressure and remain open until the system pressure is restored below the set pressure. Body is bronze for durability and a long service life.

Straight

Vent Relief Port—Vented relief ports exhaust discharge directly.

	Inlet					Relief
	Pipe Size	Thread Type	Gender	Location	Max. Pressure, psi	Port	Port Location	Steam Flow Cap., lb/hr	Set Pressure, psi	Overall Ht.	Test Mechanism	Valve Type	For Use With	Certification	Max. Temp., ° F		Each
Bronze Body—EPDM Seal



		3/4	NPT	Male	Bottom	15	Vent	Top	410	15	2 7/8"	Lever	Pop Safety	Steam	ASME BPVC.IV	250	4699K35	000000

90° Elbow

Threaded—Threaded relief ports can be attached to a drain line for remote discharge.

	Inlet					Relief
	Pipe Size	Thread Type	Gender	Location	Max. Pressure, psi	Port Pipe Size	Port	Port Fitting Connection	Port Thread Type	Port Gender	Port Location	Steam Flow Cap., lb/hr	Set Pressure, psi	Overall Ht.	Test Mechanism	Valve Type	For Use With	Certification	Max. Temp., ° F		Each
Bronze Body—PTFE-Coated EPDM Seal



		3/4	NPT	Male	Bottom	15	3/4	Pipe	Threaded	NPT	Female	Side	470	15	3 13/16"	Lever	Pop Safety	Steam	ASME BPVC.IV	250	4699K45	0000000


		1	NPT	Male	Bottom	15	1	Pipe	Threaded	NPT	Female	Side	640	15	4"	Lever	Pop Safety	Steam	ASME BPVC.IV	250	4699K46	000000
		1 1/4	NPT	Male	Bottom	15	1 1/2	Pipe	Threaded	NPT	Female	Side	1,200	15	4 1/2"	Lever	Pop Safety	Steam	ASME BPVC.IV	250	4699K55	000000
		1 1/2	NPT	Male	Bottom	15	2	Pipe	Threaded	NPT	Female	Side	1,900	15	5 1/4"	Lever	Pop Safety	Steam	ASME BPVC.IV	250	4699K65	000000
		2	NPT	Male	Bottom	15	2	Pipe	Threaded	NPT	Female	Side	2,500	15	6 9/16"	Lever	Pop Safety	Steam	ASME BPVC.IV	250	4699K7	000000
		2 1/2	NPT	Male	Bottom	15	2 1/2	Pipe	Threaded	NPT	Female	Side	3,520	15	8 1/8"	Lever	Pop Safety	Steam	ASME BPVC.IV	250	4699K8	000000
		3	NPT	Male	Bottom	15	3	Pipe	Threaded	NPT	Female	Side	4,100	15	9 1/16"	Lever	Pop Safety	Steam	ASME BPVC.IV	250	4699K9	000000

ASME-Code Fast-Acting Pressure-Relief Valves for Hot Water

Protect your water-heating system with these valves that meet ASME Code Section IV for hot water heaters and boilers. They spring fully open at the set pressure and remain open until the system pressure is restored below the set pressure. All have a threaded relief port that can be attached to a drain line for remote discharge. Valves have a durable bronze body for a long service life.

	Inlet		Relief
	Pipe Size	Location	Port Pipe Size	Port Location	Overall Ht.	Test Mechanism	Valve Type	For Use With	Certification	Temp. Range, ° F	Choose a Set Pressure, psi		Each
NPT Female Inlet and Relief Port







				Bronze Body—Silicone Seal

				3/4	Bottom	3/4	Side	5 5/16"	Lever	Pop Safety	Water	ASME BPVC.IV	33 to 250	30 , 50 , 60 , 75 , 100 , 125 , 150	4702K49	0000000


				3/4	Bottom	1	Side	5 5/16"	Lever	Pop Safety	Water	ASME BPVC.IV	33 to 250	30 , 50 , 60 , 75 , 100 , 125 , 150	4702K51	000000
				1	Bottom	1	Side	6 3/4"	Lever	Pop Safety	Water	ASME BPVC.IV	33 to 250	30 , 50 , 60 , 75 , 100 , 125 , 150	4702K61	000000
				1	Bottom	1 1/4	Side	6 3/4"	Lever	Pop Safety	Water	ASME BPVC.IV	33 to 250	30 , 50 , 60 , 75 , 100 , 125 , 150	4702K52	000000
				1 1/4	Bottom	1 1/2	Side	8 3/8"	Lever	Pop Safety	Water	ASME BPVC.IV	33 to 250	30 , 50 , 60 , 75 , 100 , 125 , 150	4702K53	000000
				1 1/2	Bottom	2	Side	10 13/16"	Lever	Pop Safety	Water	ASME BPVC.IV	33 to 250	30 , 50 , 60 , 75 , 100 , 125 , 150	4702K54	000000
				2	Bottom	2	Side	14"	Lever	Pop Safety	Water	ASME BPVC.IV	33 to 250	30 , 50 , 60 , 75 , 100 , 125 , 150	4702K62	000000

Fast-Acting Pressure-Relief Valves for Air and Inert Gas

These valves spring fully open at the set pressure and remain open until the system pressure is restored below the set pressure. They have a vented relief port to exhaust discharge directly.

NPT Male Inlet and Relief Vent


Valve With Test Lever	Valve	Valve With Test Ring

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







			Brass Body—Brass Seal

			1/8	Bottom	100	Side	90° Elbow	1 3/4"	Air, Inert Gas	-30 to 400	—	Pop Safety	5 , 10 , 15 , 20 , 25 , 30 , 35 , 40 , 45 , 50 , 55 , 60 , 65 , 70 , 75 , 80 , 85 , 90 , 95 , 100	4772K2	000000


			1/4	Bottom	200	Top	Straight	3 1/8"	Air, Inert Gas	-30 to 400	Lever	Pop Safety	5 , 10	4701K56	00000
			1/4	Bottom	300	Side	90° Elbow	2 1/2"	Air, Inert Gas	-30 to 400	—	Pop Safety	5 , 10 , 15 , 20 , 25 , 30 , 35 , 40 , 45 , 50 , 55 , 60 , 65 , 70 , 75 , 80 , 85 , 90 , 95 , 100	4772K4	00000
			1/4	Bottom	300	Side	90° Elbow	3 1/8"	Air, Inert Gas	-30 to 400	Ring	Pop Safety	10 , 15 , 20	9024K11	00000
			3/8	Bottom	200	Top	Straight	3 1/8"	Air, Inert Gas	-30 to 400	Lever	Pop Safety	5 , 10	4701K57	00000
			3/8	Bottom	300	Side	90° Elbow	2 1/2"	Air, Inert Gas	-30 to 400	—	Pop Safety	5 , 10 , 15 , 20 , 25 , 30 , 35 , 40 , 45 , 50 , 55 , 60 , 65 , 70 , 75 , 80 , 85 , 90 , 95 , 100	4772K6	00000
			3/8	Bottom	300	Side	90° Elbow	3 1/8"	Air, Inert Gas	-30 to 400	Ring	Pop Safety	10 , 15 , 20	9024K12	00000
			1/2	Bottom	200	Top	Straight	3 1/8"	Air, Inert Gas	-30 to 400	Lever	Pop Safety	5 , 10	4701K58	00000
			1/2	Bottom	300	Side	90° Elbow	2 5/8"	Air, Inert Gas	-30 to 400	—	Pop Safety	5 , 10 , 15 , 20 , 25 , 30 , 35 , 40 , 45 , 50 , 55 , 60 , 65 , 70 , 75 , 80 , 85 , 90 , 95 , 100	4772K8	00000
			1/2	Bottom	300	Side	90° Elbow	3 3/4"	Air, Inert Gas	-30 to 400	Ring	Pop Safety	10 , 15 , 20	9024K13	00000
			3/4	Bottom	300	Side	90° Elbow	5 7/16"	Air, Inert Gas	-30 to 400	Ring	Pop Safety	10 , 15 , 20	9024K14	000000


			1	Bottom	300	Side	90° Elbow	5 3/4"	Air, Inert Gas	-30 to 400	Ring	Pop Safety	10 , 15 , 20	9024K15	000000

Fast-Acting Temperature- and Pressure-Relief Valves for Hot Water

Also known as T & P valves, these open when water temperature reaches 210° F or at the set pressure. They are commonly used with water heaters and storage tanks. All spring fully open at a water temperature of 210° F or the set pressure and remain open until the system is restored below the set point. For remote discharge, valves have a threaded relief port to attach a drain line. Body is bronze for durability and a long service life.

NPT Female Inlet and Relief Port

Female ×

Female

ASME BPVC.IV Certified—Valves with _3/4 to 2 pipe size meet ASME Code Section IV for hot water.

Inlet			Relief		Set Pressure
Pipe Size	Location	Max. Pressure, psi	Port Pipe Size	Port Location	Range, psi	Temp., ° F	Shape	Hot Water Flow Cap., BTU/hr	Insertion Lg.	Valve Ht.	Overall Ht.	For Use With	Test Mechanism	Valve Type	Certification		Each







			Bronze Body—Silicone Seal

			3/4	Bottom	125	3/4	Side	125	210	90° Elbow	185,000	3"	5 7/8"	8 7/8"	Water	Lever	Pop Safety	ASME BPVC.IV, CSA Certified	9761K13	0000000


			3/4	Bottom	150	3/4	Side	150	210	90° Elbow	185,000	3"	5 7/8"	8 7/8"	Water	Lever	Pop Safety	ASME BPVC.IV, CSA Certified	9761K14	000000

NPT Male Inlet and NPT Female Relief Port


Male × Female	Male × Female With Extended Body

Extended Body—Valves with an extended body are designed for installation through thick insulation.

ASME BPVC.IV Certified—Valves with _3/4 to 2 pipe size meet ASME Code Section IV for hot water.

Inlet			Relief		Set Pressure
Pipe Size	Location	Max. Pressure, psi	Port Pipe Size	Port Location	Range, psi	Temp., ° F	Shape	Hot Water Flow Cap., BTU/hr	Features	For Insulation Thk.	Insertion Lg.	Valve Ht.	Overall Ht.	For Use With	Test Mechanism	Valve Type	Certification		Each







			Bronze Body—Silicone Seal

			1/2	Bottom	150	1/2	Side	150	210	90° Elbow	15,000	—	—	1 7/16"	3 1/4"	4 11/16"	Water	Lever	Pop Safety	CSA Certified	9761K61	000000


			3/4	Bottom	150	3/4	Side	150	210	90° Elbow	95,000	—	—	1 7/16"	3 1/4"	4 11/16"	Water	Lever	Pop Safety	ASME BPVC.IV, CSA Certified	9761K62	00000
			3/4	Bottom	150	3/4	Side	150	210	90° Elbow	105,000	—	—	3"	3 1/4"	6 1/4"	Water	Lever	Pop Safety	ASME BPVC.IV, CSA Certified	9761K63	00000
			3/4	Bottom	165	3/4	Side	150	210	90° Elbow	105,000	Extended Body	1 1/4"	2 1/2"	4 3/4"	7 1/4"	Water	Lever	Pop Safety	ASME BPVC.IV, CSA Certified	9777K22	00000
			3/4	Bottom	165	3/4	Side	150	210	90° Elbow	1,438,000	Extended Body	1 5/8"	3 1/2"	6 5/8"	10 1/8"	Water	Lever	Pop Safety	ASME BPVC.IV, CSA Certified	9777K32	000000
			3/4	Bottom	165	3/4	Side	150	210	90° Elbow	1,438,000	Extended Body	3 5/8"	5"	8 5/8"	13 5/8"	Water	Lever	Pop Safety	ASME BPVC.IV, CSA Certified	9777K42	000000
			1	Bottom	165	1	Side	150	210	90° Elbow	2,135,000	—	—	2"	6 1/4"	8 1/4"	Water	Lever	Pop Safety	ASME BPVC.IV, CSA Certified	9777K52	000000
			1	Bottom	165	1	Side	150	210	90° Elbow	2,135,000	—	—	4"	6 1/4"	10 1/4"	Water	Lever	Pop Safety	ASME BPVC.IV, CSA Certified	9777K62	000000
			2	Bottom	150	1 1/2	Side	150	210	90° Elbow	1,200,000	—	—	3"	8 1/2"	11 1/2"	Water	Lever	Pop Safety	ASME BPVC.IV, CSA Certified	9761K17	000000

Fast-Acting Pressure-Relief Valves for Ultra-Low-Pressure Steam

Choose these valves for small steam-heating boilers requiring pressure relief between 5 psi and 12 psi. They spring fully open at the set pressure and remain open until the system pressure is restored below the set pressure. All have a bronze body for durability and a long service life.

Straight

Vent Relief Port—Vented relief ports exhaust discharge directly.

	Inlet				Relief
	Pipe Size	Thread Type	Gender	Location	Port	Port Location	Overall Ht.	Test Mechanism	Valve Type	For Use With	Max. Temp., ° F	Choose a Set Pressure, psi		Each
Bronze Body—EPDM Seal



		3/4	NPT	Male	Bottom	Vent	Top	2 7/8"	Lever	Pop Safety	Steam	250	5 , 6 , 8 , 10 , 12	4699K11	000000

90° Elbow

Threaded—Threaded relief ports can be attached to a drain line for remote discharge.

	Inlet				Relief
	Pipe Size	Thread Type	Gender	Location	Port Pipe Size	Port	Port Fitting Connection	Port Thread Type	Port Gender	Port Location	Overall Ht.	Test Mechanism	Valve Type	For Use With	Max. Temp., ° F	Choose a Set Pressure, psi		Each
Bronze Body—EPDM Seal



		3/4	NPT	Male	Bottom	3/4	Pipe	Threaded	NPT	Female	Side	3 13/16"	Lever	Pop Safety	Steam	250	5 , 6 , 8 , 10 , 12	4699K12	0000000


		1	NPT	Male	Bottom	1	Pipe	Threaded	NPT	Female	Side	4"	Lever	Pop Safety	Steam	250	5 , 6 , 8 , 10 , 12	4699K13	000000

Heat-Activated Threaded Pressure-Relief Discs

Also known as fusible plugs, these discs have a metal core that melts at a set temperature to exhaust discharge directly and allow unrestricted flow. Install these one-time-use discs in pipelines and tanks.

500 psi Maximum Pressure—These discs should not be used in a system with an operating pressure greater than 500 psi.

Maximum Operating Temperature—Exceeding the maximum operating temperature decreases service life and may cause the disc to open below its melting temperature.

	Inlet
	Pipe Size	Location	Relief Port Location	Max. Pressure, psi	Max. Operating Temp., ° F	Overall Ht.	Disc Material	Valve Type		Each
NPT Male Inlet and Vent Relief Port







				Brass Body—165° F Melting Temperature

				1/4	Bottom	Top	500	100	3/4"	Bismuth, Cadmium, Lead, Tin	Rupture Disc	2764N11	000000


				3/8	Bottom	Top	500	100	3/4"	Bismuth, Cadmium, Lead, Tin	Rupture Disc	2764N13	00000
				1/2	Bottom	Top	500	100	7/8"	Bismuth, Cadmium, Lead, Tin	Rupture Disc	2764N15	00000




						Brass Body—212° F Melting Temperature

						1/4	Bottom	Top	500	150	3/4"	Bismuth, Lead, Tin	Rupture Disc	2764N12	00000


						3/8	Bottom	Top	500	150	3/4"	Bismuth, Lead, Tin	Rupture Disc	2764N14	00000
						1/2	Bottom	Top	500	150	7/8"	Bismuth, Lead, Tin	Rupture Disc	2764N16	00000

ASME-Code Fast-Acting Pressure-Relief Valves for Water

These valves meet ASME Code Section VIII for use with water pressure vessels. They spring fully open at the set pressure and remain open until the system pressure is restored below the set pressure. All have a threaded relief port that can be attached to a drain line for remote discharge. Body is bronze for durability and a long service life.

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







				Bronze Body—316 Stainless Steel Seal

				1/2	Bottom	3/4	Side	7 1/2"	Pop Safety	ASME BPVC.VIII	Water	-60 to 406	20 , 30 , 40 , 50 , 60 , 70 , 80 , 90 , 100 , 125 , 150 , 175 , 200 , 225 , 250 , 275 , 300	6270T11	0000000


				3/4	Bottom	3/4	Side	7 1/2"	Pop Safety	ASME BPVC.VIII	Water	-60 to 406	20 , 30 , 40 , 50 , 60 , 70 , 80 , 90 , 100 , 125 , 150 , 175 , 200 , 225 , 250 , 275 , 300	6270T12	000000
				1	Bottom	1 1/4	Side	9"	Pop Safety	ASME BPVC.VIII	Water	-60 to 406	20 , 30 , 40 , 50 , 60 , 70 , 80 , 90 , 100 , 125 , 150 , 175 , 200 , 225 , 250 , 275 , 300	6270T13	000000
				1 1/2	Bottom	2	Side	13 1/4"	Pop Safety	ASME BPVC.VIII	Water	-60 to 406	20 , 30 , 40 , 50 , 60 , 70 , 80 , 90 , 100 , 125 , 150 , 175 , 200 , 225 , 250 , 275 , 300	6270T16	000000