Introduction
This manual provides essential information for the proper installation, operation, and maintenance of the Watts Series 335 ASME rated Boiler Pressure Relief Valve. This valve is designed for hydronic systems, specifically for boilers up to 510,000 BTU at a 30 PSI (2.11 bar) set point. Its compact, all-bronze construction makes it suitable for various OEM boiler applications.
Figure 1: Front view of the Watts 30 PSI Pressure Relief Valve, showing the bronze body and the pressure relief lever.
Safety Information
Always follow local codes and regulations during installation and maintenance. Ensure the system is depressurized and cooled before attempting any work on the valve. Wear appropriate personal protective equipment (PPE).
- Do not tamper with the factory set pressure.
- Ensure proper discharge piping is installed to safely route discharged water.
- Regularly inspect the valve for signs of corrosion or damage.
Setup and Installation
The Watts 0342691 Pressure Relief Valve is designed for straightforward installation. It features a 3/4-inch female threaded inlet and a 3/4-inch FNPT outlet.
- Preparation: Ensure the boiler system is completely shut down, depressurized, and cooled. Drain any water from the system if necessary.
- Remove Old Valve (if applicable): Carefully unthread the existing pressure relief valve from the boiler.
- Apply Thread Sealant: Apply an appropriate thread sealant (e.g., PTFE tape or pipe dope) to the male threads of the new Watts valve.
- Install New Valve: Thread the new valve into the boiler's pressure relief valve port. Tighten securely with a wrench, ensuring not to overtighten.
- Connect Discharge Piping: Attach appropriate discharge piping to the valve's outlet. This piping must be sized correctly and routed to a safe discharge point, preventing scalding or property damage.
- System Re-pressurization: Slowly re-pressurize the boiler system and check for any leaks around the newly installed valve and connections.
Figure 2: Side view of the Watts 30 PSI Pressure Relief Valve, showing the compact design and connection points.
Operating Principles
The Watts 0342691 is an automatic pressure relief valve designed to protect hydronic heating systems from over-pressurization. It is factory-set to open at 30 PSI (Pounds per Square Inch). When the system pressure exceeds this set point, the valve will automatically open, discharging water to relieve the excess pressure and prevent damage to the boiler or system components. Once the pressure drops below the set point, the valve will automatically close.
The valve also features a manual test lever. This lever allows for periodic manual testing of the valve's operation. When the lever is lifted, the valve will open, discharging water. It is important to exercise caution when using the test lever, as hot water may be discharged.
Maintenance
Regular maintenance ensures the longevity and proper function of your pressure relief valve.
- Annual Inspection: It is recommended to inspect the valve annually for any signs of corrosion, leaks, or damage.
- Manual Testing: The manual test lever should be operated at least once a year to ensure the valve is not seized and can open freely. When testing, lift the lever briefly to allow a small amount of water to discharge, then release it. Ensure the valve reseats properly without dripping. Note: Some experienced users advise against frequent manual testing on older systems due to the risk of dislodging sediment and causing a leak. Consult a qualified technician if unsure.
- Cleaning: Keep the exterior of the valve clean. Do not use harsh chemicals that could damage the bronze finish.
Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| Valve constantly dripping or leaking |
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| Valve does not open when pressure is high |
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Specifications
Figure 3: The Watts 30 PSI Pressure Relief Valve demonstrating its compact size, approximately 2.9 inches (7 cm) in height.
| Attribute | Value |
|---|---|
| Model Number | WATTS - 118946 |
| Material | Bronze |
| Inlet Connection Size | 3/4 Inches |
| Inlet Connection Type | Female Threaded |
| Outlet Connection Size | 3/4 Inches |
| Outlet Connection Type | FNPT |
| Maximum Operating Pressure | 30 PSI (2.11 bar) |
| BTU Rating | Up to 510,000 BTU |
| Number of Ports | 2 |
| Dimensions (L x W x H) | 3 x 2.3 x 1.8 inches |
| Weight | 0.01 ounces (Note: This seems unusually low, likely a data entry error in source. Actual weight for such a valve would be higher.) |
| Specification Met | ASME Section IV |
Warranty Information
Specific warranty details for this product are not provided in this manual. Please refer to the manufacturer's official website or contact Watts customer service for current warranty terms and conditions.
Support and Contact
For technical assistance, replacement parts, or further information, please contact Watts customer support or visit their official website.
Watts Official Website: www.watts.com
Watts Store on Amazon: Visit the Watts Store
