Watts LF100XL-150210 3/4 In Lead Free Self Closing Temperature And Pressure Relief Valve, 150 psi, 210 degree F, Test Lever, Extension Thermostat

Yes, if the tapping is 3/4 inch NPT. The LF100XL-150210 has a 3/4 inch male NPT inlet that threads into the tank opening and a 3/4 inch female NPT outlet for the discharge piping. Shank length is 1-1/8 inches, so the thermostat seats through a standard tank boss rather than a thick-wall tapping.

It opens on pressure at 150 psi and on temperature at 210 degrees F, which is the combination used on higher pressure water heaters and storage tanks rather than the common 150/210 residential setting on a low pressure tank. It protects on both counts, so a tank that overheats without over-pressurizing still gets relieved.

Size it by BTU input, not gallons. The LF100XL-150210 is rated 200,000 BTU/hr pressure steam discharge and 105,000 BTU/hr temperature steam discharge. The temperature rating is the limiting number on a water heater, so the heater's input must not exceed 105,000 BTU/hr. Anything larger needs a higher capacity relief valve.

It is. The body is a lead free copper silicon alloy, which is what lets it go on potable hot water heaters and storage tanks in jurisdictions enforcing lead free plumbing rules. It is also listed as Buy American Act compliant, USA, which matters on government and institutional specs.

Yes, it uses a 4 inch copper extension thermostat. The longer probe reaches past insulation and tank wall into the stored water, so it senses actual water temperature instead of the tapping. If the existing valve on the heater has a short probe, this extended version is not a drop-in unless the tank boss depth allows the 4 inch probe to sit in the water.

Yes. The LF100XL-150210 is a self closing T&P valve with a manual test lever, so maintenance staff can lift and flush the seat on a schedule without pulling the valve. Self closing means it reseats on its own once temperature and pressure fall back below the 210 F / 150 psi settings.

Yes, and it pipes off the 3/4 inch female NPT outlet, so the drain line is 3/4 inch minimum, full size to the termination point. The discharge line is not supplied with the valve. Keep it the same size the whole run, no reductions, since this valve can dump up to 200,000 BTU/hr of steam on a pressure event.

The manufacturer part number is LF100XL-150210, carried under Watts item number 556000 in the LF100XL series. That series designation is the lead free version, so quoting LF100XL rather than 100XL keeps you on the potable water valve.