Water Hammer Arrestor, also known as Pulsation Dampener, are used to absorb the shock when water flowing in a piping system suddenly stops due to fast closing shutoff valves. This device protects against annoying and potentially damaging effects of water hammer. What is the Design of our Water Hammer Arrestor? Our L-Type Water Hammer Arrestor are designed with Rubber Air Chamber that absorbs pulse momentums caused by water hammer effect to effectively decrease shocks and banging within pipeline. Where should a water hammer arrestor be installed? Normally, Water Hammer arrestor are installed at corner of pipeline that close to check valve or on/off valves, where the water hammer mostly occurred.