摘要 |
Joints or other discontinuities in live gas pipelines are sealed by spraying the joint or discontinuity with a coating material by means of an explosion-proof coating device, capable of traversing long lengths of pipe. The coating device is inserted into the pipe and uses a halogen lit explosion-proof camera for locating joints or other discontinuities in the pipe. The preferred coating material is a high build epoxy-type elastomeric polyurethane, which quickly cures in the presence of pressurized flowing gas. Several joints or discontinuities, spanning several hundred feet of pipe, may be coated using a single excavation. |