Safety, Relief & Pressure Reducing Valves
Pop Safety Valves vs. Relief Valves
There is a difference!
A Pop Safety Valve is used with gases, which include air and steam. Their design always includes a huddling chamber which utilizes the expansion forces of these gases to effect quick opening (“popping”) and closing actions. The difference between the opening and closing pressures is termed “blowdown”.
A Relief Valve is normally used for liquid service, although safety valves may also be used. Ordinarily, relief valves do not have an accentuated huddling chamber nor a regulator ring for varying or adjusting blowdown. Therefore, they operate with a relatively lazy motion, slowly opening as pressure increases and slowly closing as pressure decreases. Such relieving action affords suitable protection for vessels or systems where there is no need for instantaneous release of large volumes of fluids.
Kunkle Safety and Relief Valves
High Reliability Safety Relief Valves For Pressures To 6500 psi. Sizes 1/4H through 6H. All Types and Connections: Brass, Bronze, Aluminum, Steel and Alloys.
Kunkle Series 6252
Cast iron safety valve for steam or air. A.S.M.E. Standard – N.B. Certified. Pressure settings to 250#.
Kunkle Series 537
Cast iron or bronze safety valve for hot water heating boilers. A.S.M.E. Standard – N.B. Certified. Pressure settings to 160#.
Kunkle Series 6000
Bronze safety valve for steam, air, or gas. A.S.M.E. Standard – N.B. Certified. High capacity, side outlet.
When ordering, please specify: Series #, pressure setting, medium (steam, water, air), flanged or threaded connection, inlet/outlet sizes, body material, and orifice type.
Bell & Gossett ASME Hot Water Relief Valves
Bell & Gossett bronze ASME safety relief valves offer the highest BTUH rating available on the market for valves of their size. B&G ASME safety relief valves are available in a wide range of capacities to closely match the BTUH output range of hot water heating boilers, direct fired hot water heaters, heat exchangers and other pressure vessels.
Bell & Gossett ASME Safety Relief Valves
Bell & Gossett bronze ASME safety relief valves offer the highest BTUH rating available on the market for valves of their size. B&G ASME safety relief valves are available in a wide range of capacities to closely match the BTUH output range of hot water heating boilers, direct fired hot water heaters, heat exchangers and other pressure vessels.
ORDERING INFORMATION | ||||
---|---|---|---|---|
Relief Setting PSIG | BTU’s Per Hour Capacity | |||
Bronze Body | Iron Body | |||
790 Series | 1170 Series | 3301 Series | 4100 Series | |
30 | 790,000 | 1,170,000 | 3,300,000 | 4,100,000 |
36 | 900,000 | 1,330,000 | 3,800,000 | 4,600,000 |
45 | 1,065,000 | 1,575,000 | 4,500,000 | 5,515,000 |
50 | 1,160,000 | 1,710,000 | 4,900,000 | 5,990,000 |
75 | 1,615,000 | 2,385,000 | -- | -- |
100 | 2,075,000 | 3,060,000 | -- | -- |
125 | 2,535,000 | 3,735,000 | -- | -- |
Inlet | 3/4" | 1" | 1-1/2" | 2" |
Outlet | 3/4" | 1" | 2" | 2" |
Bell & Gossett Pressure Reducing Valves
Bell & Gossett B7-12 Reducing Valve
This low pressure reducing valve is equipped with a low inlet pressure check valve and removable strainer. It is suitable for use in buildings with a maximum of three floors.
Bell & Gossett B-38, FB-38, B-38TU, and FB-38TU Reducing Valves
These low pressure reducing valves are equipped with a low inlet pressure check valve and removable strainer. Models with an “F” prefix feature fastfill. Models ending in “TU” feature a 1/2" sweat/NPT union.
Bell & Gossett Dual-Unit Valves
Combine functions of reducing and relief valves. The B&G pressure reducing valve is coupled with the noncode relief valve, providing overpressure protection as well as the fill function.
ORDERING INFORMATION | ||||
---|---|---|---|---|
ORDER # | Component Valves | Body | Connections | |
Boiler | Fill | |||
8 | AB | Iron | 1/2" NPT | 1/2" NPT |
B-38 | Brass | |||
8TU | A8 | Iron | 1/2" Union NPT Sweat | |
B-38TU | Brass | |||
F-3 | A3 | 1/2" NPT | ||
FB-38 | ||||
F-3TU | A3 | 1/2" Union NPT Sweat | ||
FB-38TU | ||||
F-8 | A8 | Iron | 1/2" NPT | |
FB-38 | Brass | |||
F-8TU | A8 | Iron | 1/2" Union NPT Sweat | |
FB-38TU | Brass |
Hoffman Series 2000 Pilot Operated Steam Regulators
The Hoffman Series 2000 Pressure Regulating Line includes 27 main valves, 14 pilot valves, various wells and 4 hardware kits. They are designed to meet a wide range of temperature, pressure and capacity requirements and provide accurate, dependable, low maintenance operation. Any model main valve can be used with any pilot valve or combination of pilot valves to provide complete flexibility to meet your various needs.
To Order Series 2000 Valves, Specify:
- Main Valve Model Number
- Size and Connection Type of Main Valve Port Type (Full, Normal or Reduced)
- Any Pilot Valve Styles needed
- Pilot Hardware Packages needed
SERIES 2000 MAIN VALVE ORDERING INFORMATION | |||
---|---|---|---|
MODEL # | SIZES | CONNECTION | MAX PRESSURE |
2100 | 1/2" to 2" | Threaded | 250 psig |
2150 | 3/4" to 2" | 30 psig | |
2200 | 2" to 6" | Flanged | 125 psig |
2250 | 30 psig | ||
2300 | 250 psig |
Hoffman Model 754 Self-Contained Pressure Reducing Valve
The Hoffman Model 754 is used for controlling steam pressure, where an accurate tight closing valve is required, on applications such as small sterilizers, cooking tables, heating coils, unit heaters and pressing machines. Single seated for dead-end or continuous service.
Johnson Controls Pressure Activated Water Valve
These V46 flanged valves modulate water or glycol in liquid cooled refrigeration condensers. Direct acting valves open on a pressure rise. Reverse acting valves open on pressure decrease and are generally used for bypass or heat pump operation.
Reverse Acting Valves: Element: 30" capillary w/1/4" flare nut.
Johnson Controls Companion Flanges and Gaskets

Johnson Controls Navy NAVSEA Certified Valves
Navy or marine valves for salt water service are equipped with naval cast bronze bodies. Metal internal parts coming in contact with salt water are of monel.
Johnson Controls Maritime Valves
Element: 30" capillary w/sweat conn.
Spence Pilot-Operated Pressure Regulator
Spence offers the most complete line of interchangeable pilots and main valves to give you a custom-designed control system … at no extra cost!
With Spence, you can select from over 70 different pilots and 5 main valves to meet your exact control requirements. One size fits all sizes of main valves. By simply switching interchangeable pilots, one main valve can handle different control functions. Multiple control functions can be achieved by using two or more pilots on a single main valve.
Select from standard side or optional integral mountings and a wide choice of ratings and control ranges. Spence main valves are offered in iron, bronze or steel construction in 3/8'' through 12'' sizes.
Match functional and operating requirements of the Type ED Pressure Regulator with the Spence modular design concept.
Here’s how:
1. Choose a main valve to suit your operating conditions.
MAIN VALVES | |||
---|---|---|---|
Body Material | IRON | STEEL | BRONZE |
Size Range | 3/8'' to 12'' | 3/8'' to 10'' | 3/8'' to 2'' |
Cv Range | 0.5 to 1600 | 0.5 to 700 | 0.5 to 30 |
Max. Pressure Rating | 250 PSIG | 600 PSIG | 250 PSIG |
Max. Temperature Rating | 450°F | 750°F | 450°F |
2. Add one or more pilot valves to meet your functional needs.
PILOT VALVES | ||||
---|---|---|---|---|
FUNCTION | MODE | TYPE OF CONTROL | ||
Mechanical | Pneumatic | Electronic | ||
Temperature Control | Heating | • | • | • |
Cooling | • | • | • | |
Pressure Control | Reduction | • | • | • |
Back | • | • | • | |
Differential | • | • | ||
Vacuum | • | • | ||
Temperature plus Pressure | Heating | • | • | • |
Cooling | • | • | ||
On/Off Flow Control | Auto Startup | • | ||
Manual | • | • | • | |
Auto-trip | • | |||
Level Control | Liquid | • | • | |
Speed Control | Pump Governor | • |
Spence Water Pressure Reducing Valves
These regulators are designed for dead-end water pressure reduction service. Because of their quick response, they are ideally suited for installations— such as domestic water service—where flow is intermittent and changes rapidly. Due to their balanced design, they are insensitive to varying initial pressure.
Body Material | Iron |
Size Range | 1'' to 6'' |
Cv Range | 4.1 to 138 |
Reduced Pressure Range | 10 to 80 PSIG |
Max. Pressure Rating | 200 PSIG |
Max. Temperature Rating | 200°F |