A compression fitting is a mechanical, heat-free pipe joint in which a soft metal ring (the olive or ferrule) is placed over the pipe and driven by a threaded nut into a tapered seat in the fitting body, so tightening converts axial thread travel into radial plastic deformation of the ring against both pipe wall and seat, producing a metal-to-metal pressure seal that simultaneously grips the pipe. The joint's integrity depends on full pipe insertion to the internal shoulder and on a bounded compression range: below it the ferrule does not deform enough to seal, above it the ferrule or thread yields and the seal is permanently compromised. This belongs to pipework jointing within plumbing and mechanical services, standing as the demountable alternative to permanent metallurgical joints such as soldered or brazed capillary fittings and to elastomer-sealed push-fit joints.
A compression fitting is a mechanical, heat-free pipe joint in which a soft metal ring (the olive or ferrule) is placed over the pipe and driven by a threaded nut into a tapered seat in the fitting b…