| 摘要 |
<p>A service riser (10) comprises a steel jacket (11) around a polyethylene pipe (12) which terminates in the riser at a transition zone (20). The transition zone (20) comprises a retainer sleeve (30) inserted in the end of the pipe (12) and sealed thereto by an O-ring (38). The retainer sleeve (30) extends out of the pipe (12) and is provided with grooves (46) separated by lands (48) on which an elastomeric sealing band (52) is received. The tube (11) is swaged down forming a swage groove (56) around the retainer sleeve (30) compressing the gasket (52) to a large extent over the lands (48) and a lesser extent over the grooves (46), the ideal compression for the gasket (52) being arranged somewhere between such degrees of compression. By this means the ideal degree of compression at some regions of the gasket (52), forming an annulus around the retainer sleeve (30), is guaranteed, despite tolerances in the dimensions of the tube (11) (especially) as well as the band (52) and sleeve (30).</p> |
