Spiral pipe into operation to the site, first according to equipment and fittings position exhaust pipe, and in the field will be specific length of each pipe of measurement is good, mark the specific size and arrangement position in order to facilitate an interface condemnation, under the use of the crane tube, down tube during hoisting nylon sling to protect the pipe insulation.
1, repair mouth
Repair ports concentrated in the factory pipeline processing is completed, in order to ensure the quality of welding, before welding underwent a comprehensive inspection, correction, make pipe end, bevel angle, blunt edge, roundness, etc., are in line with their counterparts in joint size requirements, the need for individual pipe done in the field beveling process, the use of gas welding cutting, remove the slag and then use the wheel polished smooth.

Counterpart operating procedures: Check the interface connector size → clear breech → determine and adjust the position of the steel pipe longitudinal welds staggered → first conduit looking straight counterparts adjust gap dimension → pipeline cable counterparts leveling looking straight → spot welding

2, Welding
Interface welding using arc welding, again backing, survived two times, and each time the welding seam are finished, each arc welding point lead to be staggered. Repair welding pipe joints should be preceded by mouth, slag, bevel angle pipe end to end face, blunt edge, the gap should be consistent with specification; clip can not help strip welding or heating counterparts gap narrowing gap welding. Counterparts should be flush with the inner wall, with a long 300mm ruler in order around the inner wall abutting the interface, the wrong port allows partial check should be 0.2 times the difference between the wall thickness, and no greater than 2mm.