The WA and WR types are designed to seal PVC pressure pipe on which a connector is fitted at one end. The unique design of the WR, with vertical ribs and low depth, means that the same size of plug can be used to seal both the plain end and connector end of the tube. This simplifies storage routines. The WA type plugs are longer than the WR and, to ensure full-length insertion, the distance from the end of the pipe down to the seal ring must be greater.
