Step 6 · Install the New Angle Stop
Take your new angle stop and unscrew the compression nut. Slide the new nut onto the cleaned copper pipe first, with its threads facing towards you. Then, slide the new brass ferrule onto the pipe, with its tapered end facing away from you (towards the wall). Push the new angle stop body onto the pipe until it seats firmly against the ferrule. Slide the nut up to the valve body and hand-tighten it. Now, using two wrenches again (one for counter-torque), tighten the compression nut an additional one-half to three-quarters of a turn past hand-tight. Do not overtighten, as this can crush the ferrule and pipe, causing a leak.