Pipe insulation at the interface should be preceded by repair welding mouth, gouging, bevel angle pipe end to end face, blunt edge, gap, should meet the following requirements;clip can not help strip welding or heating counterparts gap narrowing gap welding.

Counterpart pipe insulation should be flush with the inner wall, 300mm long straightedge should be used in order around the inner wall abutting the interface, the wrong port of tolerance should be 0.2 times the wall thickness, and no greater than 2mm.

When the counterpart of the weld location should meet the following requirements: a straight pipe from the upper section of the center plane between the two butt weld, nominal diameter greater than or equal to 150mm, not less than 150mm, when the nominal diameter less than 150mm, should not be smaller than the outer tube path. The pipe should;be measured from the interface center counterparts at 200mm flatness, when the pipe when the nominal diameter of less than 100mm, tolerance of 1mm, when nominal pipe diameter greater than or equal to 100mm, tolerance is 2mm. But the full-length to allow deviation 10mm.

On opening pipe insulation should meet the following requirements: Do not dry tube longitudinal weld ring opening to; any position on the pipeline shall prescribe hole; the pipe,section or may not be on the tube openings; straight pipe length should not be used less than 800mm short section of stitching.