Sioux Chief's CPVC Mini-Rester eliminates water hammer in CPVC plumbing lines. While CPVC may absorb some of the effects of water hammer due to its flexibility, water hammer arresters are still necessary. It is very damaging to the pipe and fittings if the CPVC is forced to absorb the effects of water hammer over long periods of time. Even if the pipe manufacturer warrants that they are not necessary, they may still be required to satisfy the code. Codes do not make an exception to their water hammer control requirements for plastic pipe. The CPVC socket solvent welds to tube in rough-in and retrofit applications. Sioux Chief.