| 摘要 |
<p>PCT No. PCT/GB90/01308 Sec. 371 Date Apr. 1, 1991 Sec. 102(e) Date Apr. 1, 1991 PCT Filed Aug. 20, 1990 PCT Pub. No. WO91/02918 PCT Pub. Date Mar. 7, 1990.A joint between pipes (12, 14) each having a liner (16, 18) of polyolefin such as polythene. The pipes are spaced apart and the liner protrudes from each and is joined to its neighbor by a fusion coupling (20). The pipes are interconnected by a shell (24, 26, 28) and epxoy cement grout (34) fills the space between the liner and the shell. The liner is inserted in the pipe after it has been reduced in diameter by passing it through a die. The pressure of gas or liquid within the liner in use is greater than the liner can withstand alone but the grout transfers pressure loading to the shell. In modifications the coupling is replaced by a PECAT coupling or by flanged couplings joined to the pipes by butt fusion or by electrofusion directly or using electrofusion couplers. The liner may be locked in position using electrofusion fittings to prevent change of dimensions by reversion.</p> |
