| 摘要 |
An increased efficiency method and apparatus for lining a section of pipe with a cement mortar. After a wet cement mortar has been applied to a cleaned interior surface of a pipe, carbon dioxide is introduced into the freshly lined section of the pipe in such quantity that a crust of calcium carbonate will be formed on the interior surface of the wet cement mortar lining as the carbon dioxide reacts with calcium compounds of the wet cement mortar in a relatively short period of time. This crust is provided to protect the underlying mortar from scouring, while tolerating a low-velocity flow of water, until the normal hardening of the underlying mortar through hydration can take place so as to substantially reduce the out-of-service time of the section of pipe which is being lined. In order to provide a saturated carbon dioxide gas condition within the water main section for effective and rapid formation of the crust but with a minimum waste of carbon dioxide gas, the carbon dioxide gas pressure is regulated to maintain a positive pressure just slightly greater than atmospheric, bellows preferably provided to precisely indicate pressure.
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