Watts LFMMVM1-US 1/2 1/2 In Lead Free Thermostatic Mixing Valve, Solder Union End Connections, Adjustable Out 80-120 F

Yes. The LFMMVM1-US is a 1/2 inch valve with socket (solder) connections on all three ports: hot inlet, cold inlet, and outlet are each 1/2 inch socket, so they sweat directly onto 1/2 inch copper tube. There are no threaded adapters to buy, but you do need to be able to sweat all three joints in place, which matters in a tight cabinet or close to a water heater tank fitting.

Adjustable from 80 to 120 degrees F, and it leaves the factory set at 105 degrees F. Outlet accuracy is plus or minus 7 degrees F, so a 120 degree setting can land as high as 127. If you are dialing in a scald-sensitive fixture, set it and then check the temperature at the tap rather than trusting the dial alone.

Rated capacity is 13 GPM at 45 PSI with a usable flow range of 0.5 to 20 GPM. The 0.5 GPM low end is the part that decides most jobs: it will hold temperature on a single lavatory faucet without dropping out, and the 13 GPM top end covers a small group of fixtures or a residential water heater outlet. For a large gang restroom or a whole commercial building main, size up past a 1/2 inch valve.

It needs 30 PSI minimum static pressure to work, and the hot and cold supplies have to be within 25 percent of each other in pressure. That second one trips people up more often than the first: if the cold is on street pressure and the hot comes off a tank behind a partly closed valve or a fouled line, the mix wanders even though both lines are above 30 PSI. Balance the two supplies before blaming the valve. Maximum working pressure is 150 PSI.

No cold water bypass on this valve. If the cold supply drops out, there is no path that lets unmixed hot water through to the fixture. That is what you want for scald protection at a lavatory. It does mean the valve is not the right choice where you need flow to continue during a cold-side interruption, which is a deliberate tradeoff on a point-of-source tempering valve rather than a shortcoming.

Yes. The body is a lead free copper silicon alloy and the valve is flagged lead free, which is what lets it go on potable domestic water lines. The LF prefix in the model number is Watts' designation for that construction. Body finish is rough bronze, so it is meant to be concealed or in a mechanical space rather than exposed as a finished trim piece.

It carries a USA Buy American Act compliant designation, which is the flag institutional and government procurement asks for on a federally funded project. Order it by manufacturer part number LFMMVM1-US 1/2.