To reduce the water hammer by providing a pressure reflecting part in a position where a reflected pressure can be reflected to an opening and closing valve at the terminal of a piping within the closing time of the opening and closing valve.

A feed header 3, a feed pipe 4, and a faucet 5 are connected to a feed main pipe 1 through a water meter 2, and a hot water supplying device 6, a hot water feed header 7, a hot water pipe 8 and a faucet 5 are connected to a pipe branched from the water meter 2. The feed header 3, the hot water feed header 7 and a check valve built in the water meter 2 are taken as pressure reflecting parts. The piping lengths from the faucet 5 to the feed header 3, the hot water feed header 7, and the water meter 2 are set to prescribed lengths, whereby the reflected pressure can be reflected to the faucet 5 within the closing time of the faucet 5, and since the raised pressure caused by the closing operation of the faucet 5 is reflected before the valve part of the faucet 5 is closed, and released through the discharge port of the faucet 5, the water hammer can be reduced. Thus, the water hammer can be reduced without giving a sense of incompatibility in the handle operation.