| 摘要 |
PROBLEM TO BE SOLVED: To provide a seal material capable of improving water tightness while reducing a maximum insertion force required when inserting a spigot into a socket.SOLUTION: The seal material comprises: a first salient 19 formed in the periphery of a valve part 18; a second salient 20 formed at a socket depth end part of the valve part 18; a taper part 28 formed to reduce the diameter from the inner periphery of a heel part 17 toward the inner periphery of the second salient 20; and a third salient 21 formed at the taper part 28 to project on the radial inner side, in which the bore of the third salient 21 is smaller than the external diameter of the spigot as well as being larger than the bore of the second salient 20, and a gap between the first salient 19 and the third salient 21 is compressed in a radial direction A so as to keep water tightness between the socket and the spigot. |
