Watts 0121428 Valve

The Watts 0121428, professionally recognized as the 40XL-7-150 or LF40XL7-150-1, is a heavy-duty T&P relief valve engineered for high-capacity commercial water heater protection. This 1-inch NPT temperature and pressure relief valve features an extended 7-inch thermostat element, ensuring precise thermal sensing in thick-walled tanks or insulated vessels. Rated for a steam discharge capacity of 2,134,000 BTU/hr, it is a critical safety component for preventing catastrophic pressure vessel failure. The lead-free copper silicon alloy construction ensures compliance with potable water regulations while maintaining high mechanical strength. Designed for a set pressure of 150 PSI and a temperature relief setting of 210°F, this ASME HV rated valve provides reliable blow-down performance. It is a direct replacement T&P valve for large-scale boilers and storage tanks requiring high-volume throughput and robust corrosion resistance in demanding HVACR environments.

• High-Capacity Discharge: Certified 2,134,000 BTU/hr rating makes this suitable for large commercial water heating systems.
• Extended Thermostat: The 7-inch probe length ensures accurate immersion in the hot water zone, preventing delayed activation in deep-insulated tanks.
• Durable Construction: Features a lead-free copper silicon alloy body and a stainless steel spring for lasting performance in high-temperature applications.
• Regulatory Compliance: Meets ASME Section IV and CSA XL21 standards for safety-critical pressure relief.
• Universal Compatibility: Interchanges seamlessly with Watts LF40XL-7 and standard 1-inch NPT configurations.

What is the difference between the 40XL-7 and the standard 40XL?
The "7" designation indicates a 7-inch extended thermostat element, whereas the standard model utilizes a 2-inch probe. This extension is required specifically for tanks with thick insulation to ensure the sensing element reaches the water column.

Can this valve be installed in any orientation?
For proper HVACR safety compliance, the 0121428 must be installed so that the sensing element is immersed in the top 6 inches of the water tank, where the water is hottest. Vertical installation is industry standard.

Is the Watts 0121428 rated for steam applications?
While it has a steam BTU discharge rating, it is designed for water heating systems. Its primary function is to relieve pressure and temperature in potable water storage tanks, not for use on pure steam boilers.

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.