CONNECTION STRUCTURE OF DRAIN PIPE

摘要

PROBLEM TO BE SOLVED: To uniform the use amounts of plural sets of vacuum valves even in a state where a flow rate is small.SOLUTION: A connection structure includes: a drain pipe 5 that is provided with an inner layer pipe 16 formed of a resin material, a foam resin layer 17 provided on an outer peripheral surface 16a of the inner layer pipe 16 and a skin layer 18 provided on an outer peripheral surface 17a of the foam resin layer 17; and a pipe joint 7 that connects the drain pipe 5 and a vertical pipe for drain water. Between the drain pipe 5 and the pipe joint 7, an adapter 6 is arranged, which is provided with a socket 8 to which a tip part 5a of the drain pipe 5 is internally fitted and a spigot 9 inserted into an end part 11a of the pipe joint 7. In the end part 11a of the pipe joint 7, a fastening mechanism 20 fastening the spigot 9 and holding it is included.