Watts 530C-STD 3/4 3/4 In Brass Poppet Type Calibrated Pressure Relief Valve, 1/2 IN Outlet, Adjustable 50-175 psi

Inlet is 3/4 inch male NPT, outlet is 1/2 inch female NPT. So it threads into a 3/4 inch female NPT tapping or tee on the supply line, and the discharge side takes 1/2 inch pipe. If the opening you are working with is female on the line side, you're fine; if it's male, you need a coupling or a different valve.

No. The 530C is a pressure only relief valve, with no temperature probe element. A water heater requires a combination temperature and pressure (T&P) relief valve. Use the 530C where you need thermal expansion or overpressure protection on a cold or tempered line, such as downstream of a pressure reducing valve or backflow preventer, and keep the T&P on the heater itself.

It is not a lead free valve. That rules it out for potable water service in jurisdictions enforcing the lead free requirement for wetted components. Use it on non potable applications, and specify a lead free relief valve where the line carries drinking water.

Rated to 300 psi maximum working pressure and 180 degrees F maximum temperature. The 300 psi rating is the body limit, well above the 175 psi top of the adjustment range, so the valve body is not the constraint when you set it high. The 180 degree ceiling means it suits cold and tempered water, not steam or high temperature boiler service.

The 530C-STD 3/4 is flagged Buy American Act compliant with USA origin, which is what a federal, municipal, or public school procurement spec typically asks for on plumbing valves. The body is brass.

Yes, run the discharge. The outlet is 1/2 inch female NPT, so drop 1/2 inch pipe from it to a safe point of discharge, full size and without reducing or valving the line. Nothing is included for that run, so plan on the fittings and pipe as part of the install.

Poppet design, which means a spring loaded disc seats against the port and lifts when line pressure beats the spring setting. It reseats once pressure drops back. Because it is calibrated, the setpoint is marked and repeatable rather than guessed, and it is adjustable between 50 and 175 psi. Diaphragm style relief valves are the alternative where the application calls for one; the 530C is the poppet version.