Watts 0121408 Valve

The Watts 0121408 (Series LF40L-2) is a high-capacity automatic reseating temperature and pressure relief valve designed for heavy-duty commercial water heaters and large storage tanks. Engineered with a lead-free copper silicon alloy body, this valve ensures compliance with stringent safety standards while providing a massive steam relief capacity of 1,808,000 BTU/hr. It features a 1-inch NPT male inlet and a 1-inch NPT female outlet, specifically calibrated for 125 PSI pressure relief and a 210°F temperature relief limit. This model serves as the direct lead-free replacement for legacy units like the 0154820 and 40L-2-125.

Built for the rigorous demands of mechanical rooms, the Watts 0121408 valve includes a 2-inch thermo-bonded coated thermostat to prevent mineral buildup and ensure accurate sensing. The unique non-mechanical seat-to-disc alignment and tamper-resistant bonnet screws provide long-term reliability in high-cycle environments. For modern facility management, this unit is equipped with a SentryPlus Alert discharge line flood sensor, which can be integrated into a Building Automation System (BAS) via an optional connection kit to monitor for emergency discharge events.

• ASME Rated and CSA Listed: Meets ANSI Z21.22 requirements for high-output commercial boilers and water heaters.
• Massive Relief Capacity: Rated at 1,808,000 BTU/hr to handle industrial-scale thermal expansion and pressure build-up.
• Coated Thermostat: High-durability 2-inch probe with specialty coating to resist lime and scale accumulation in hard water applications.
• Smart Monitoring Ready: Pre-installed flood sensor allows for remote detection of valve activation to mitigate property damage.
• Lead-Free Construction: Complies with all safe drinking water regulations for potable water systems.

Common Questions

What is the difference between the LF40L and LF40XL models?
The Watts LF40L typically features a standard or short thermostat for direct tank tapping, whereas the LF40XL utilizes an extended thermoset for installation in the hot water outlet piping. Always verify the required probe length for your specific tank configuration.

Can I use this valve for solar thermal applications?
Yes, the high-capacity steam rating and 210°F relief threshold make the 0121408 suitable for solar thermal water heating systems where high temperature and pressure fluctuations are common.

Is the flood sensor active right out of the box?
The sensor is physically installed on the valve, but integrating it with your alerts requires a separate SentryPlus Alert connection kit to communicate with your building management system 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.