| 摘要 |
A method and apparatus are provided for sealing the opening in the sidewall of a fluid carrying main during replacement of a service tee or the like comprising a gate valve, means on end of said gate valve for engaging the end of a service tee remote from the main, a plug wrench having an elongate stem adapted to pass through said gate valve in the open position, closure means on the other end of said gate valve having a passage adapted to sealingly and slidably pass said stem through the gate valve to remove a screw plug in the end of the service tee remote from the main and to receive the screw plug and wrench above the gate valve while the gate valve is closed, a stopper rod interchangeable with the elongate stem of the plug wrench in the passage in the closure means, said stopper rod having an axial passage, a resilient elongate member abutting one end of said stopper rod, an intermediate hollow shaft threaded in the hollow passage of the stopper rod and extending through the resilient member to expand the plug radially on relative rotation with respect to the stopper rod, a threaded jack shaft extending through and threadingly engaging the hollow intermediate shaft and through the resilient member whereby on relative rotation of the jack member and the stopper rod, the expanded resilient member is raised into engagement with the wall of the main around the opening therein to seal the same.
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