What Is a Water Arrestor

Water hammer arrestors are used to absorb the shock when water flowing in a piping system suddenly stops due to fast closing shutoff valves, dishwashers, and clothes washers. This action protects against annoying and potentially damaging effects of water hammer.

Where should a water hammer arrestor be placed?

Exactly where to place the hammer arrestor will depend on the actual piping arrangement. The best places are either close to the pump, isolation or check valve that is originating the hammer, or at more distant points where the pipe changes direction, for example at the top of a pump riser.

Are water hammer arrestors necessary?

The general rule is that water hammer arrestors are required on all quick closing valves. … If these hoses are reasonably flexible, chances are they will absorb the potential water hammer before it returns to the piping system.