Step 6 · Install the New Angle Stop
Take your new quarter-turn angle stop. Ensure the valve handle is in the 'off' position (perpendicular to the valve outlet). Unscrew the compression nut from the valve body. Slide the new nut onto the prepared copper pipe, with the threads facing you. Then, slide the new brass ferrule onto the pipe, ensuring its tapered end points towards the end of the pipe where the valve will sit. Push the new valve body firmly onto the pipe until it bottoms out against the ferrule. Slide the nut up and hand-tighten it onto the valve body. Now, use two wrenches again: one to hold the valve body steady and one to tighten the compression nut. Tighten the nut about one-half to one full turn past hand-tight. Do not over-tighten.