Bob:–most pipe noises that occur when the water is turned on at a fixture are a result of expansion or contraction of the pipe or tube as it changes from the ambient temperature. The noise is a result of the piping sliding back and forth on the framing that supports it. To cure the noise problem install nylon or polyethylene type pipe clamps. This type of pipe clamp will prevent the pipe from making the characteristic tick.tick.tick noises as it changes length especially on the hot water lines. Lots of luck….Bud..