| 摘要 |
<p>The joint consists of the end of one pipe inserted in the sleeve of the neighbouring pipe, the annulus between them being filled with jointing agent e.g. a lead stopper. A sealing substance is pressed over the surfaces of the pipes at hte joint and held compressed against the pipe walls by a heat shrinkable plastic film sheath wrapped around the pipes over the joint, the film is then heated causing it to shrink onto the pipes providing a permanent pressure against the sealing substance, pref. a butyl rubber and bitumen mixture.</p> |
