Joining Plastic Supply Pipes

Push-fit Joints:

When the pipe is inserted, an ‘O’ ring seals in the water in the normal way and (depending on the model) a special plastic grab ring, or a collett with stainless steel teeth, grips the tube securely to prevent water under mains pressure forcing the joint apart. Joints fitted with collects can be disconnected easily, but to dismantle the other type of push fit joint, it is necessary to remove the retaining cap and prize open the grab ring using a special tool. Push-fit joints are more obtrusive than their solvent welded equivalents, but are much faster to assemble. Stratford Plumbers can work with push-fit joints.


Using Grab Ring Joints:

Cut Polybutylene pipe to length with the special shears that are supplied by the manufacturer, alternatively, use a sharp craft knife. Provided that you make the cut reasonably square, the joint will be watertight. Push a metal support sleeve into the pipe, and, if necessary, smear a little silicon lubricant around the end of the pipe and inside the socket. Push the prepared pipe firmly a full 25mm (1in) into the socket. As the joint can revolve freely around the pipe after connection without breaking the seal, there is no problem with aligning tees and elbows with other pipe runs. A Stratford Plumber uses grab ring joints.


Connecting Metal to Plastic Plumbing:

Special adapter couplings are needed in order to connect most types of plastic pipe to copper or galvanized-steel plumbing. To join Polybutylene pipe to copper, insert a metal support sleeve, then use a standard brass compression joint, or use a push fit connector to join copper pipes to a Polybutylene run. Cut and de-burr the copper pipe carefully before pushing it into the joint.