Watts 0556007 Valve

When you are specking out high-capacity domestic hot water systems, the Watts 0556007 40XL-4-125 is the industry standard for reliable thermal and overpressure protection. As a veteran-grade automatic reseating temperature and pressure relief valve, it is engineered specifically for commercial water heaters and storage tanks where safety is non-negotiable. This unit features a 1-inch NPT male inlet and 1-inch NPT female outlet, delivering a substantial steam discharge capacity of 1,808,000 BTU/hr to handle high-demand applications. The 4-inch extension thermostat is designed with a specialized thermo-bonded coating to prevent mineral scaling and galvanic corrosion, ensuring accurate sensing even in hard water environments. This 125 psi relief valve is the factory-authorized replacement for legacy models 0163720, 40XL-4-125, and the lead-free LF40XL-125-1. Construction consists of a heavy-duty bronze body with tamper-resistant bonnet screws and a reinforced test lever, providing long-term structural integrity in demanding mechanical rooms. For contractors focused on ASME Section IV and CSA technical specifications, this valve ensures precise 210°F temperature relief and consistent reseating performance.

• Maximum Protection: High-capacity 1,808,000 BTU/hr rating for large-scale boiler and commercial water heater safety.
• Enhanced Durability: Rugged 1" bronze body and non-mechanical seat-to-disc alignment minimize maintenance call-backs.
• Corrosion Resistance: Thermo-bonded 4" thermostat prevents scale buildup for reliable temperature sensing.
• Field Proven: Direct technical replacement for multiple legacy Watts 40XL and 0163720 configurations.
• Precision Control: Factory set at 125 psi with automatic reseating functionality after emergency discharge.

Is the Watts 0556007 compatible with lead-free requirements?
Yes, this model replaces the LF40XL-125-1 and meets modern standards for potable water systems in commercial installations.

Can this valve be installed on the cold water inlet?
No, per technical code, these T&P valves must be installed with the thermostat probe immersed in the hottest water within the top 6 inches of the tank to ensure accurate thermal relief.

What is the difference between the 40L and 40XL series?
The 40XL features an extended 4-inch thermostat probe, making it suitable for heaters with thicker insulation or specific outlet manifold configurations where a standard short probe cannot reach the water core.

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.