Sch 40 PVC plugs are used to plug off a fitting in PVC systems. Plugs cannot be used with pipe and are only designed to work with glue or threaded fittings. Plugs are made with a spigot or threaded end so that they will work with any fitting in the PVC system. Sch 40 plugs are pressure tested to meet all industry standard and can handle heat up to 140 degrees Fahrenheit.