We're doing a minor remodel of our master bathroom, and I have replaced the 30+ year old diverter and nearby pipe with a new one from Delta. Now when any faucet in the house is turned on and off quickly, there is a hammering or banging sound coming from the diverter (2 or 3 bangs). Trying to hold the diverter and nearby pipes firmly still does not reduce the noise, though the diverter is certainly well secured to the brace. The photo below shows the extent of the plumbing I had to do. (Note the wonderful polybutylene at the right which transitions via a Sharkbite to the CPVC.)
Are newer pressure balancing valves subject to this kind of hammering? That seems like a possibility since the old valve certainly did not balance the pressure.
The only other thing I can think of is that I knocked some pipe strap/hanger loose somewhere, but why would it cause the sound to come from the diverter area?