Watts 0556002 Valve

The Watts 0556002 (Model LFLL100XL-150-3/4) is a lead-free transition for the legacy 0066132, engineered specifically for high-efficiency water heaters and storage tanks. Designed as a dual-function T&P relief valve, it provides autonomous protection against excessive thermal expansion and over-pressurization. This model features an extended shank capable of penetrating up to 2-1/2 inches of tank insulation, eliminating the need for additional extension nipples that can weaken the connection point. The 3/4" MNPT inlet and FNPT outlet integrate seamlessly into standard piping layouts, while the thermo-bonded coating on the extension thermostat resists mineral buildup to ensure accurate temperature sensing. With a dedicated 150 psi pressure rating and a 210°F temperature relief threshold, this ASME rated and CSA listed valve is the standard for contractors managing systems up to 105,000 BTU/hr. Its copper alloy body and stainless steel spring are built for heavy-duty plumbing and HVACR environments where durability is non-negotiable.

• Extended Shank Design: Specialized 2.5-inch inlet length bypasses thick insulation on modern water heaters.
• Lead-Free Reliability: Constructed with a lead-free copper alloy to meet all potable water safety standards.
• Corrosion Resistance: Thermo-bonded coating prevents scale accumulation on the thermostat probe.
• Dual Protection: Mechanically manages both temperature and pressure relief in a single, self-closing unit.
• Certified Performance: Fully ASME Section IV and ANSI Z21.22 compliant for professional installations.

Is the Watts 0556002 compatible with my high-efficiency tank?
Yes, the LFLL100XL is specifically designed for the "new generation" of tanks that utilize 2-1/2 inches of insulation. If your heater has standard insulation, a standard shank model like the LF100XL may be sufficient, but the 0556002 ensures the sensing element is correctly positioned in the top 6 inches of the tank.

Can this valve replace the older 0066132 or LL100XL models?
The 0556002 is the direct lead-free updated version for those legacy part numbers. It maintains the same 150 psi set point and 3/4-inch sizing, making it a drop-in HVAC replacement part for existing systems.

What is the BTU capacity for this relief valve?
This model is rated for water heaters and hot water storage tanks with a heat input of up to 105,000 BTU/hr. For larger commercial boilers, verify the total BTU capacity against ASME rating requirements.

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.