PVC (PolyVinyl Chloride) ball valves are widely used plastic shut off valves. The valve contains a rotatable ball with a bore. By rotating the ball a quarter turn, the bore is inline or perpendicular to the piping and the flow is opened or blocked. PVC valves are durable and cost efficient. Furthermore, they can be used for a wide variety of media, including water, air, corrosive chemicals, acids and bases. Compared to brass or stainless steel ball valves, they are rated for lower temperatures and pressures and have a lower mechanical strength. They are available with different piping connections, such as solvent sockets (glue connection) or pipe threads. Double union, or true union valves, have separate pipe connection ends that are fixed to the valve body by a threaded connection. The valve can easily be removed for replacement, inspection and cleaning.