Cushion Clamps

Cushion clamps in steel with a bonded polypropylene liner, 1/4" through 2", from nVent Caddy.

The liner does two jobs at once, and both matter more than the clamp's cost suggests.

It isolates the pipe electrically. A bare steel clamp in contact with copper sets up a galvanic cell wherever moisture reaches the joint, and the pipe corrodes at that point rather than along its length — a pinhole leak exactly where the clamp sits is the signature.

And it isolates acoustically. Pipe expands and contracts as water temperature changes, and a rigid clamp turns that movement into the ticking heard through a finished ceiling. Water hammer transmits the same way. The polypropylene absorbs both and lets the pipe move slightly rather than binding it.

Do not overtighten. A cushion clamp crushed down onto the pipe stops it sliding and defeats the purpose — the clamp should hold position without pinching.