ANTIFREEZE STRUCTURE OF WATER SUPPLY PIPE

摘要

PROBLEM TO BE SOLVED: To solve a problem of being difficult for easily and economically preventing freeze of a water supply pipe. SOLUTION: This water supply pipe is composed of a main pipe branched off from a trunk pipe, and a branch pipe branched off from the main pipe. A drain pipe is connected to the main pipe, and a drain valve is arranged in the drain pipe. The drain valve opens when a water temperature in the main pipe becomes a prescribed temperature or less, and water in the main pipe is drained from the drain pipe. The drain valve closes when the water temperature becomes the prescribed temperature or more. A check valve is arranged between the main pipe and the drain pipe for preventing water in the drain pipe from flowing in the main pipe.