Second, dig repair repair (mainly used for ≥ φ89 pipe cracks)ĭumping repair is the pipe has been the site of the crack, with a plasma arc to completely cut off, and dig out the width of 150mm, than the two ends of the visible cracks at the end of 20mm pipe base material.

Welding direction from left to right, the order of welding for the layer by layer from bottom to top.Ĥ, after welding, the appearance of the weld to be flat and weld height h ≤ 1mm, width ≤ 4mm, done by color inspection qualified to use after normal use. Everything is thoroughly cleaned, each connector should be staggered around 15mm, to ensure that no defects. The length of the groove is the distance between the cut holes, and through the hole grinding out the weld and the base metal transition surface, and the groove on both sides of the oil, rust and other debris clean up.Ģ, the use of ZX7-400A welder, DC reverse, welding consumables A402, φ3.2mm for rendering, filling and cover, welding current of 110A.ģ, the use of arc welding primer, even with arc welding and cover, and single-channel primer, double-channel filling, 3-channel cover. And then use the angle grinder grinding groove angle α = 60 °, gap b = 3.2mm, blunt edge p = 1.5mm groove. So, the welding of the crack repair has become an important maintenance method.įirst, the crack for direct welding (mainly used for ≤ φ89 pipe cracks)ġ, do the preparatory work before welding, from the two ends of the crack at the end of each 10mm drill φ6mm crack hole, has prevented the grinding process of welding crack propagation. As the material process requirements are high, once the base metal and filler material alloying elements are not complete, improper welding process, working condition is not good, pipe corrosion, work stress and other reasons will cause serious defects in pipeline cracks, will bring to the production A serious risk. 310S is a heat-resistant stainless steel, with good oxidation resistance, corrosion resistance, widely used in ion-exchange membrane electrolysis of the alkaline pipeline.

Pipa crack