Step 6 · Install and Tighten the Coupling

This is the step people usually slow down on. Go finger-tight first, then a quarter turn. No rush — replay the clip whenever it helps.

Insert the body of the compression coupling into the gap you cut, ensuring that each end of the pipe is fully seated inside the coupling's stops. Slide the ferrules and nuts up to the coupling body. Hand-tighten both nuts onto the coupling body until they are snug. Now, use two wrenches. Place one wrench on the hexagonal center of the coupling body to hold it steady. Use the second wrench to tighten one of the nuts. Tighten it until it feels firm, then give it an additional quarter- to a half-turn. Do not overtighten. Repeat this process for the nut on the other side.