Stop noisy pipes from banging with the Sioux Chief Mini-Rester 1/2 in. This straight water hammer arrester features a 1/2 in. Male iron pipe connection that can be installed vertically, horizontally or at any angle in between on new rough-in or retrofit installation with 1/2 in. female iron pipe fittings. Water hammer occurs when the flow of moving water is suddenly stopped by a closing valve. This can lead to fractured pipe joints, leaking valves, burst laundry hoses, and premature failure of water heaters and other appliances.