发明名称 |
REPLACING MAINS |
摘要 |
A method is provided for replacing a length of a branch gas main 1 joined to a spine main 2 with a length of replacement main 7 having an outer diameter smaller than the inner diameter of the branch main. In the method access is gained to the bore of the branch main and one end of the replacement main 7 is fed along the branch main 1 via the access point and towards the spine main 2 until the branch main 1 has been replaced. During and after the feeding step gas is prevented from entering any clearance 20 between the mains 1 and 7 by means of a head 9 attached to the leading end of the main 7. After the feeding step a sealant 25 is injected into the branch main 1 to form a seal within the clearance 20.
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申请公布号 |
CA2054824(C) |
申请公布日期 |
1996.08.20 |
申请号 |
CA19912054824 |
申请日期 |
1991.11.01 |
申请人 |
BRITISH GAS PLC |
发明人 |
ELGAR, ANTHONY DENNIS;SALES, BRIAN THOMAS;PARKES, ADRIAN SYDNEY |
分类号 |
F16L1/024;F16L1/00;F16L55/10;F16L55/12;F16L55/16;F16L55/18;(IPC1-7):F16L55/18 |
主分类号 |
F16L1/024 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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