PURPOSE: To prevent corrosion and deterioration of a stainless steel pipe due to entry of moisture in the ground and underground water into a gas pipe by mounting a water-tight layer which is made of synthetic resin and has rubber elasticity on the surface of stainless steel pipe.
CONSTITUTION: A stainless steel pipe 1 is made like bellows and spiral corrugation and provided with flexibility. Further, a water-tight layer 2 which is made of synthetic resin and has rubber elasticity is mounted on the stainless steel pipe 1 to prevent entry of moisture in the ground and water on the ground into a gas pipe which is imbedded in the ground and prevent corrosion and deterioration of the stainless steel pipe 1 due to water. Consequently, gas does not leak, and sufficient reliability is obtained even when the gas pipe is used for a long time. Thus formed water-tight layer 2 is covered by a plastic sheath 3 to obtain desired gas pipe.
IKEDA TOMOHIKO
SUNATSUKA HIDEO
IIDA TADASHI
YOSHINO AKIRA
