Watts 0276500 Valve

For high-capacity pressure protection in commercial and industrial hydronic systems, the Watts 0276500 (Series 174A-1 1/2-30) is a heavy-duty ASME Section IV safety relief valve designed specifically for hot water heating boilers. This 1-1/2 inch bronze boiler pressure relief valve is factory-set at 30 PSI, providing a high steam relief capacity of 2,020,000 BTU/hr. Built with a rugged bronze body and a stainless steel spring, the 174A series utilizes a non-metallic disc-to-metal seating surface to ensure positive shut-off and resistance to corrosive water conditions. The NPT threaded female inlet and outlet connections are engineered for high-flow emergency relief, with a seat located above the drain to prevent sediment accumulation from fouling the mechanism. This hot water space heating boiler relief valve features a non-mechanical seat-to-disc alignment that eliminates sticking and freezing, ensuring the automatic reseating function maintains system integrity after a pressure spike. As an veteran tech, you know this Watts 174A 30 PSI valve is the standard for protecting large-scale boiler equipment from over-pressurization.

• ASME Rated Performance: Certified for ASME Section IV applications with a massive 2,020,000 BTU/hr relieving capacity.
• Debris-Resistant Design: The raised seat prevents water and sediment entrapment, ensuring the valve won't foul during critical relief events.
• Non-Stick Alignment: Specialized seat-to-disc engineering prevents the valve from sticking or freezing even after long periods of inactivity.
• High-Temperature Durability: Features a water seal made of high-temperature resistant material to isolate the spring assembly from discharge.

Is the Watts 0276500 suitable for potable water systems?
No, this valve is designed for non-potable hot water space heating and domestic supply boiler applications. It does not comply with the Lead-Free requirements of the Safe Drinking Water Act.

What is the correct discharge piping for this 1-1/2" relief valve?
The discharge line must be the same diameter as the valve outlet (1-1/2" NPT), pitch downward to a safe point of disposal, and contains no shut-off valves or obstructions.

Why is my boiler relief valve dripping when the gauge is below 30 PSI?
Dripping often indicates thermal expansion issues or scale buildup on the seat. Check your expansion tank or try manually cycling the test lever to clear debris from the seating surface.

This item is not eligible for free shipping.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.