Watts 0121479 Valve

For high-demand hydronic systems and hot water space heating boilers, the Watts 0121479 (model LF174A-3/4-125) provides critical overpressure protection. This lead-free boiler pressure relief valve is engineered with a lead-free copper silicon alloy body to ensure durability and compliance in various installations. Featuring a 3/4 inch NPT female inlet and outlet, it manages a broad 2,070,000 BTU/hr capacity at a fixed 125 PSI relief setting. The non-metallic disc-to-metal seating and non-mechanical disc alignment prevent the valve from sticking or freezing even in harsh water conditions. Built with a stainless steel spring and an integrated test lever, this ASME Section IV compliant valve is a reliable drop-in replacement for the standard Watts LF174A 3/4" 125. It effectively isolates working parts from water discharge using a high-temperature resistant seal, ensuring long-term seat integrity and preventing sediment accumulation.

• Maximum BTU Capacity: Rated for up to 2,070,000 BTU/hr, making it suitable for large-scale domestic and commercial heating equipment.
• Corrosion Resistance: Lead-free construction and high-quality silicon alloy body provide superior resistance to corrosive water and mineral buildup.
• Reliable Reseating: The automatic reseating design and raised seat prevent water or sediment from being trapped, ensuring a tight seal after operation.
• Contractor-Grade Installation: Standard 3/4" NPT threads and identical specs to the LF174A-3/4-125 ensure easy field replacement with no piping modifications.

Is the 0121479 interchangeable with the standard LF174A-3/4-125?
Yes, the 0121479 is the exact ordering code for the LF174A in a 3/4-inch configuration with a 125 PSI factory setting.

Can this valve be used as an operating control?
No, this is a safety relief device designed for emergency overpressure protection only. It should never be used to regulate system pressure.

Does this model include a flood sensor?
While the LF174A series supports SentryPlus Alert technology, this specific model (0121479) is the standard relief valve unit. Check for the "FS" suffix if you require the integrated flood sensor and connection kit.

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.