Watts 0009821 1/4 In Lead Free 3-Way Small Water Pressure Regulator, 3-50 psi

Both ends are 1/4 inch female NPT on the Watts LF263A, model 9821. Inlet and outlet are the same size and type, so it drops into a 1/4 inch NPT line with male nipples on each side. No union or adapter is included, so plan your nipples and sealant at install.

The LF263A adjusts anywhere from 3 to 50 psi (0.2 to 3.4 bar) and leaves the factory set at 15 psi (1.0 bar). If your equipment needs something other than 15 psi, you adjust it on site. Anything above 50 psi on the outlet is outside this valve's range and calls for a different regulator.

No. There is no thermal expansion bypass on this regulator, so it will not relieve pressure back toward the supply when a heater cycles. On a closed system you still need a thermal expansion tank or a relief path. If the job specifically calls for a bypass feature, specify a Watts reducing valve that lists thermal expansion bypass.

It is a 3-way regulator, meaning the body carries a third port in addition to inlet and outlet. On a small industrial line that port is what lets downstream pressure bleed off instead of creeping up when there is no flow, which is the usual failure mode with a dead-end two-way regulator feeding an instrument or a small piece of equipment. If your line is a standard domestic water service and you just need pressure knocked down, a conventional two-way water pressure reducing valve is the simpler choice.

Body and trim are both lead free brass on the LF263A, which is what the LF prefix in the series designation indicates. The internal disc is Buna-N. Note the catalogued application is industrial, so match it to the duty you have in front of you.

Up to 140 F (60 C). That covers typical domestic hot water service but not boiler or steam duty. The low end is 0 F (-18 C), so the valve itself tolerates cold storage, though water in the line will still freeze well before that.

No gauge ships with it, but the body has a gauge tapping, so you can thread a gauge in to read and verify your set point. Order the gauge separately. Given that the valve arrives preset at 15 psi and adjusts over a 3 to 50 psi band, a gauge is the only practical way to dial it in.

There is no integral strainer on this valve. On a 1/4 inch line feeding a small regulator with a Buna-N disc, any grit that gets to the seat will hold it off and cause creep, so an upstream strainer or filter is worth installing where the water is not clean. If you want the screen built into the valve, look at a Watts pressure reducing valve model that lists an integral stainless strainer instead.

It carries no corrosion resistant coating, just the lead free brass body and trim. Bare brass is fine in ordinary interior mechanical rooms and equipment enclosures; for washdown, coastal, or chemically aggressive locations, pick a regulator that specifically lists a protective coating or a stainless body.