Watts 0121544 Relief Valve

The Watts 0121544 (Series LF174A) is a high-capacity boiler pressure relief valve designed specifically for hot water space heating applications. Engineered with a lead-free copper silicon alloy body, this 1.5-inch valve provides critical overpressure protection for large-scale hydronic systems. This specific model, also identified as LF174A-1 1/2-100, is factory-set at 100 PSI and features a significant discharge capacity of 5,290,000 BTU/hr (5,290K), making it a standard choice for heavy-commercial and industrial boilers. The non-mechanical seat-to-disc alignment is a key design element, preventing common issues like sticking or freezing due to mineral deposits. With NPTF female threaded connections and a stainless steel spring, this valve ensures reliable automatic reseating after a pressure event. It is built to ASME Section XIII standards and includes a test lever for mandatory annual maintenance checks. For modern facilities, this unit often comes integrated with SentryPlus Alert technology, allowing for flood detection monitoring when connected to a building management system.

• High BTU Discharge: Capable of handling 5,290,000 BTU/hr to match large boiler outputs.
• Lead-Free Reliability: Constructed from lead-free copper silicon alloy for compliance and durability.
• Maintenance Minded: Features a raised seat located above the drain to prevent sediment fouling and a manual test lever.
• Precision Setting: Factory-set at 100 PSI for high-pressure hydronic configurations.
• Seamless Integration: Direct replacement for Watts 174A-1 1/2-100 and LF174A-1 1/2-100.

What is the maximum temperature rating for the Watts 0121544?
This valve is designed for hot water applications with a maximum operating temperature of 250°F.

Can I use this 100 PSI valve on a 30 PSI boiler system?
No. You must select a relief valve with a set pressure that corresponds to the maximum working pressure of your boiler. Using a 100 PSI relief valve on a low-pressure 30 PSI boiler is unsafe and violates code.

Is the flood sensor functionality ready out of the box?
The valve includes the SentryPlus Alert sensor, but activation requires a separate connection kit for integration with a BMS or cellular gateway.

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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.