WATTS Safety Relief Valve, Bronze
Safety relief valves, also known as pressure relief valves, open when a preset pressure point is reached and release fluid until the pressure drops to an acceptable level. These valves control or limit the pressure in a system. This is necessary because pressure could build up and disrupt a pro...cess, cause instrument failure or start a fire. Watts relief valves (174A Series) are used to prevent the build-up of pressure in a wide range of applications involving water, oil and air.Read more
Style | Model | Seat Material | BtuH | Disc Material | Spring Material | Factory Set Pressure | Inlet Size | Outlet Size | Overall Height | Price | |
---|---|---|---|---|---|---|---|---|---|---|---|
A | 3/4 174A-050 | Bronze | 950,000 | Silicone | Stainless Steel | 50 psi | 3/4" | 3/4" | 5.125" | €167.24 | |
A | 2 174A-150 | Bronze | 14,370,000 | Silicone | Stainless Steel | 150 psi | 2" | 2" | 11.625" | €1,379.02 | |
B | 1 174A-050 | Bronze | 1,470,000 | Silicone | Stainless Steel | 50 psi | 1" | 1" | 5.75" | €455.45 | |
A | 2 174A-100 | Bronze | 9,970,000 | Silicone | Stainless Steel | 100 psi | 2" | 2" | 11.625" | €1,697.89 | |
B | 1 1/2 174A-150 | Bronze | 7,630,000 | Silicone | Stainless Steel | 150 psi | 1.5" | 1.5" | 9" | €1,196.30 | |
B | 1 1/4 174A-125 | Bronze | 5,370,000 | Silicone | Stainless Steel | 125 psi | 1.25" | 1.25" | 8.375" | €810.14 | |
B | 1 1/4 174A-100 | Bronze | 4,399,000 | Silicone | Stainless Steel | 100 psi | 1.25" | 1.25" | 8.375" | €786.31 | |
B | 1 1/4 174A-075 | Bronze | 3,429,000 | Silicone | Stainless Steel | 75 psi | 1.25" | 1.25" | 8.375" | €757.71 | |
A | 3/4 174A-075 | Bronze | 1,320,000 | Silicone | Stainless Steel | 75 psi | 3/4" | 3/4" | 5.125" | €177.57 | |
B | 1 1/4 174A-150 | Bronze | 6,340,000 | Silicone | Stainless Steel | 150 psi | 1.25" | 1.25" | 8.375" | €714.83 | |
A | 2 174A-125 | Bronze | 12,170,000 | Silicone | Stainless Steel | 125 psi | 2" | 2" | 11.625" | €1,697.89 | |
A | 2 174A-075 | Bronze | 7,770,000 | Silicone | Stainless Steel | 75 psi | 2" | 2" | 11.625" | €1,459.26 | |
C | 2 174A-050 | Bronze | 5,575,000 | Silicone | Stainless Steel | 50 psi | 2" | 2" | 11.625" | €1,459.26 | |
D | 1 174A-150 | Bronze | 3,795,000 | Silicone | Stainless Steel | 150 psi | 1" | 1" | 5.75" | €456.92 | |
A | 3/4 174A-150 | Bronze | 2,445,000 | Silicone | Stainless Steel | 150 psi | 3/4" | 3/4" | 5.125" | €172.95 | |
A | 3/4 174A-125 | Bronze | 2,070,000 | Silicone | Stainless Steel | 125 psi | 3/4" | 3/4" | 5.125" | €178.07 | |
A | 3/4 174A-100 | Bronze | 1,695,000 | Silicone | Stainless Steel | 100 psi | 3/4" | 3/4" | 5.125" | €178.01 | |
E | 1 174A 125 | Metal | 3,215,000 | Nonmetallic | Stainless Steel | 125 psi | 1" | 1" | 5.75" | €342.65 | |
F | 11/4 174 A | Metal | 1,682,000 | Buna-N | Brass | 30 psi | 1.25" | 1.25" | 8.375" | €559.23 | |
F | 2 174 A | Metal | 3,815,000 | Buna-N | Brass | 30 psi | 2" | 2" | 11.625" | €1,242.39 | |
E | 1 174A 75 | Metal | 2,055,000 | Nonmetallic | Stainless Steel | 75 psi | 1" | 1" | 5.75" | €423.89 | |
E | 1 174A 100 | Metal | 2,635,000 | Nonmetallic | Stainless Steel | 100 psi | 1" | 1" | 5.75" | €344.65 | |
G | 174 A-3/4" | Metal | 650,000 | Nonmetallic | Stainless Steel | 30 psi | 3/4" | 3/4" | 5.125" | €105.74 |
Working Mechanism
- Watts relief valves are installed after the pump in hydraulic systems, since they reduce pressure equal to their spring settings.
- These 174A relief valves open when a backpressure or downstream load exerts enough pressure to open the poppet or spool against its spring.
- They provide excessively pressurised fluid with an open path to the tank, with the goal of reducing work port pressure.
- As fluid pressure begins to rise, the force from that pressure is applied to the bottom of the spool or poppet.
- The relief valve opens modestly at first, bleeding as little fluid as required to maintain pressure downstream.
- The poppet or spool pushes further against the spring as downstream pressure rises so that it is equalised with hydraulic force.
Features
- Watts 174A Series relief valves are used to protect against excessive pressure in hot water heating equipment.
- They feature bronze body construction, NPT threaded female inlet & outlet (drain) connections, non-metallic disc-to-metal seating, a stainless steel spring and a test lever for ease of operation.
- Watts 174A relief valves are resistant to corrosive water conditions, sticking and freezing. They also prevent water and sediments from accumulating in the seat.
- They are ideal for emergency safety relief and should not be used as operating control valves.
Standards and Approvals
- ASME Section IV
Frequently Asked Questions
Do weather and temperature affect valve performance?
Yes, they can. For example, high ambient temperatures can affect the set pressure of the valve, whereas low ambient temperatures (combined with moisture) can make valves freeze, leading to possible malfunction.
What mounting orientation should be used to install a Watts relief valve?
We recommended vertically installing the valve. This way, it can be ensured that the valve body is self-draining and that set pressure is achieved. If the safety valve is installed in any position other than vertical and upright, it may adversely affect its performance and lifespan.
What should I check during visual inspection of a relief valve?
What causes a relief valve to fail?
Contaminants like dirt / lint / rust / sludge, or misalignment of the valve can cause it to stick and not function properly.
What is the difference between orifice and inlet size?
The orifice diameter is the diameter of the internal opening of the valve, which is used to determine the flow capacity. Inlet size refers to the interface of the valve or the size / type of the threads where you attach it.
We are here to help!
Looking for a part not listed here?
Explore More
- Shower Drains
- High Temperature Lead Wire
- Ultrasonic Flow Meter Detectors
- Belt Drive Forward Curve Blower
- Wrenches
- Flame Resistant and Arc Flash Clothing
- Sandpaper
- Fittings
- Springs
- QUANTUM STORAGE SYSTEMS Steel Louvred Panels
- SCHAEFER Air Circulator
- APPROVED VENDOR Fan And Limit Temperature Range
- BUSSMANN BBU Series Medium Voltage Fuses
- DURHAM MANUFACTURING Stationary Workstations
- WATTS Seat And Seal Repair Kits
- EATON BR Series Spa Panels
- EATON ELC Series Logic Controller Graphics Panels
- HOSHIZAKI Ice Machine Stands
- BROWNING SSF3S 100 Series Light Duty Stamped Steel Three Bolt Flange Mounted Ball Bearings