Watts 0274751 Valve

The Watts 0274751 (Model 174A-M3) is a high-capacity boiler pressure relief valve engineered for critical overpressure protection in large-scale hot water heating systems. Designed for professional HVAC installation, this 3/4-inch FNPT valve features a rugged bronze body construction and is ASME Section IV certified, ensuring compliance with strict safety codes for commercial and residential hydronic applications. With a fixed factory pressure setting of 125 PSI and a massive steam relief capacity of 2,070,000 BTU/hr, this unit is built to manage extreme thermal expansion without compromising system integrity.

The Watts 174A-M3 utilizes a non-mechanical, seat-to-disc alignment that eliminates the risk of "sticking" or "freezing" due to prolonged inactivity or mineral buildup. Its unique design places the seat above the drain level, preventing sediment accumulation from fouling the seal. For contractors looking to modernize their hydronic heating safety protocols, this model includes the SentryPlus Alert discharge line flood sensor, which can be integrated into building management systems to monitor for unwanted discharge events and prevent water damage before it escalates.

• ASME Section IV Certified: Verified performance for high-output boilers requiring up to 2,070,000 BTU/hr capacity.
• Corrosion-Resistant Internals: Features a high-temperature resistant water seal that isolates the stainless steel spring and working parts from discharge water.
• Advanced Flood Detection: Built-in flood sensor allows for optional BAS integration via Modbus or Wi-Fi connectivity kits.
• Reliable Reseating: Non-metallic disc-to-metal seating ensures a tight seal after emergency operation and prevents premature leaking.
• Technician-Friendly Design: Standard 3/4" female NPT connections and a sturdy test lever facilitate efficient maintenance and system testing.

Is this valve suitable for potable water systems?
No, the 174A series is designed strictly for non-potable hot water heating and boiler applications. It does not meet the low-lead requirements for drinking water systems.

What is the maximum operating temperature for the Watts 0274751?
This valve is rated for a maximum operating temperature of 250°F (121°C), making it ideal for high-temperature hydronic loops.

Does this valve replace the older 174 series?
Yes, the 0274751 is a direct replacement for previous 3/4" 174A-125 models and is upgraded with better-performing non-mechanical alignment and sensor readiness.

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.