Step 6 · Tighten the Connections
Just as with removal, use two wrenches for tightening. Hold the body of the new angle stop steady with channel-lock pliers or an adjustable wrench. Use a second adjustable wrench to tighten the compression nut. The general rule is to tighten one full (360-degree) turn past finger-tight. This compresses the ferrule onto the pipe, creating the seal. Do not over-tighten. Once the valve is secure, re-attach the faucet supply line to the outlet on the new angle stop. Hand-tighten the nut, then use an adjustable wrench to give it a final quarter-turn.