| 摘要 |
Lining or sleeve of polyolefin material is used as a melt adhesive to bond a sulphur-cured EPDM seal profile to the mouth of a metal pipe joint socket. The sleeve is fused by applying heat via the outer surface of the socket mouth. Pref. the outer dia. of the (elastic) seal is slightly greater than the internal dia. of the socket seat, and the internal dia. of the sleeve is slightly less than that of the seal profile, so that the joint is consolidated by elastic pressure from the seal profile. The polyolefin sleeve may be a simple tubular sleeve or an envelope made from one or two pieces of film to enclose the seal profile: surplus exposed film is subsequently removed. Pref. the polyolefin used is stabilised against degradation by light. |
