Push-fit plastic pipework is a mechanical, demountable jointing system in which a pipe end is retained inside a fitting by a gripping collet and sealed by an elastomeric O-ring, so that the joint is achieved by axial insertion alone with no heat, solder, or flux. Because the plastic pipe wall is not self-supporting under the radial load of the collet and O-ring, a rigid tubular insert (liner) must be fitted into the pipe bore to maintain roundness and guarantee the seal — a requirement that disappears when the same fitting receives rigid copper tube, which is inherently self-supporting. This belongs to plumbing and pipework jointing within building services, and it sits alongside soldered, compression, and press-fit jointing as the demountable, tool-light member of that family.
Push-fit plastic pipework is a mechanical, demountable jointing system in which a pipe end is retained inside a fitting by a gripping collet and sealed by an elastomeric O-ring, so that the joint is …