Ball Valves and Valve Assemblies

Full port, quarter-turn and the end connection

A ball valve opens and closes with a quarter turn, which makes it good for on-off duty and poor for throttling flow, because a part-open ball wears the seats. A full port valve has a bore as wide as the pipe and loses little pressure, while a standard port valve has a smaller bore and suits low-flow lines. Check the body material, such as bronze, brass, stainless steel or PVC, against the fluid and temperature.

Then read the ends. Female or male threaded ends need the same thread standard as the pipe, soldered ends, called sweat, suit copper, slip-joint ends take a nut and washer, and press ends need a press tool. An angle stop under a sink may have a different inlet and outlet, for example 1/2 inch female pipe thread in and a slip connection out, so check both sides. The pressure rating, often written as WOG, shows the water, oil or gas pressure the valve can take.

Relief, vent and radiator valves, and small valves for PC loops

Not every valve here is a ball valve. Relief valves open at a set pressure to protect a system, so the set pressure and the discharge rating must suit the equipment, and you should never plug one or swap it for a higher setting. Air release and vent valves bleed trapped air from heating systems, and radiator valves are sized and shaped by pipe size and steam or hot-water use.

Small G1/4 valves and stop fittings belong to PC liquid-cooling loops, where a valve isolates a graphics card or radiator for removal without draining the loop. Match the thread, G1/4, and the finish to your fittings. Valve boxes are different again: they are plastic covers for buried irrigation or utility valves, sized by length, width and depth.

Questions about Ball Valves and Valve Assemblies

What is the difference between full port and standard port?

A full port valve has a ball bore equal to the pipe's inside diameter, so flow is nearly unrestricted. A standard or reduced port valve has a smaller bore and is more compact, but it restricts flow a little. For pumps and long runs, full port keeps pressure loss low.

Can a ball valve be used to adjust flow?

It is meant to be fully open or fully closed. Holding it partly open wears the seats and can cause leaks or noise, because the flow cuts across the edge of the ball. Use a globe or needle valve when you need to regulate flow, and keep a ball valve for isolation.

How do I choose an angle stop for a sink?

Match the supply pipe connection, such as 1/2 inch female pipe thread or compression, and the outlet that attaches to the faucet supply line. Quarter-turn stops are quicker to operate and less likely to seize than old multi-turn ones. Check the finish for visible installations.