Watts 0358550 Regulator

When you are servicing high-demand hydronic systems, the Watts 0358550 (Series 374A) is the industry standard for reliable overpressure protection. This 3/4 inch boiler pressure relief valve is specifically engineered for hot water heating boilers with a factory-set relief pressure of 45 PSI. Designed with a robust iron body and a forged bronze inlet, it effectively manages thermal expansion in systems rated up to 875,000 BTU/hr. A standout technical feature for technicians is the seat design: it is positioned above the drain to prevent sediment accumulation and water trapping, which eliminates the common issue of the seat fouling over time. The non-mechanical disc-to-seat alignment ensures the valve will not stick or freeze, even in corrosive water conditions. This ASME rated relief valve features female NPT connections for a secure fit and includes a manual test lever for routine system safety checks. For modern facilities, it is compatible with SentryPlus Alert technology to detect excessive discharge, making it a critical component for HVAC system safety and flood prevention.

• High Steam Discharge Capacity: Rated for systems up to 875,000 BTU/hr at a 45 PSI setting, ensuring superior protection for large residential and commercial boilers.
• Foul-Resistant Design: The raised seat prevents sediment buildup and mineral deposits from compromising the seal, extending the service life of the hydronic safety valve.
• Corrosion-Resistant Internals: Features a stainless steel spring and non-metallic disc-to-metal seating to resist sticking and freezing in harsh environments.
• Simplified Installation: Standard 3/4" female NPT inlet and outlet allow for rapid integration into existing boiler piping.

What is the maximum operating temperature for this valve?
The Watts 374A-045 is designed to handle maximum water temperatures up to 250°F (121°C).

Can this valve be used as a primary operating control?
No, this is an emergency safety relief device only. It should never be used as a regulating valve or operating control for the boiler.

Is this compatible with wood or coal-fired boilers?
This specific iron body relief valve is designed for hot water space heating boilers and is not recommended for use with coal or wood-fired equipment.

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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.