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Water Safety & Flow Control


Lead Free* Automatic Re-seating Temperature and Pressure Relief Valves

Lead Free* Models Available


3/4, 1 in.. (20, 25mm)


Series LF40L, LF40XL Automatic Reseating Temperature and Pressure Relief Valves are used in commercial water heater applications to provide automatic temperature and pressure protection to hot water supply tanks and hot water heaters. They feature a Lead Free* brass body with NPT male inlet and NPT female outlet connections, unique thermostat with special thermo-bonded coating, tamper-resistant bonnet screws, automatic reseating feature, and test lever. Model LF40L has a short thermostat for installation directly in available tank tapings. Model LF40XL has an extension thermostat for installation in the hot water outlet within the allowable distance from the top of the tank. Series LF40L, LF40XL valves are ASME rated and CSA listed. Temperature Relief: 210°F (99°C), Pressure Range: 75 to 150psi (5.2 to 10.3 bar), Standard Pressure Settings: 75, 100, 125, or 150psi (5.27, 7.03, 8.79, or 10.55 bar).

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Disclaimer: Watts product dimensions in U.S. customary units and metric are approximate and are provided for reference only. For precise measurements, please contact Watts Technical Service. Watts reserves the right to change or modify product design, construction, specifications, or materials without prior notice and without incurring any obligation to make such changes and modifications on Watts products previously or subsequently sold.

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*The wetted surface of this product contacted by consumable water contains less than 0.25% of lead by weight.

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