摘要 |
Joints and leaks in pipelines or mains are sealed by injecting into the joint or leak a sealant by means of an expandible tubular pig which is moved endwise through the pipeline or main. The sealant is in the form of an anaerobically curable monomer which cures in the relatively air free conditions in the joint or leak. The pig forms within the pipeline or main an air-free space which communicates with the joint or leak and which is isolated from the fluid in the main. Nevertheless the pig is hollow to permit the flow of fluid therethrough while the joint or leak is sealed. The sealant is injected into the joint or leak by way of the space so that the sealant cures in situ in the joint or leak. |