| 摘要 |
<p>Large dia. steel pipes, for laying in the ground, are joined by internally welding at a groove. Thermal insulation is applied to the exterior surface. The ends of the coating, the uncoated parts of the ends and the insulation are covered with a layer of material which is adhesive, corrosion-resistant and melts when heated. This last layer is fused with a thin clamping plate on top, and the pipes are welded together. The ends of the coating thus fuse and the corrosion-resistant material bonds to the uncoated ends and to the coating. Method minimises the width of the trench required esp. at the joint and hence speeds up the infilling, partic. suitable for pipes of 700 mm dia. and over (welder works inside).</p> |
