These drain test plugs or drain stoppers as they are also called consist of two steel plates with a rubber insert. As the central steel wing nut is tightened, the steel plates push together and force the rubber to expand, thus creating a water tight seal within the pipe. By replacing the centre cap with a test nipple, you can then also pressure test the pipe using a drain test kit.
15" / 375mm Drain test plug.
Will fit pipes with a minimal internal diameter of 370mm and maximum internal diameter of 415mm
1" Outlet
Max allowable back pressure 5 psi.
