SSAW Pipe

 　　After removing the root of the weld, double-sided weldments should be inspected. When using the oxyacetylene flame to cut the welding fixture on the alloy pipe that has a tendency to harden, defects in the ground part will be found. Radiographic testing and ultrasonic testing The main targets of radiographic testing and ultrasonic testing are the butt joints of straight seam steel pipes and the butt joints of butt welded pipe fittings. 　　The basis for selecting the non-destructive testing method of the straight seam steel pipe is the rule of the planning document. For welded joints of titanium, aluminum and aluminum alloys, copper and copper alloys, nickel and nickel alloys, radiographic testing methods should be used. For welds that are prone to cracks, radiographic and ultrasonic inspections should be performed after a certain period of time after the welds have cooled. 　　When the main pipe in the casing has a circumferential seam weld, the weld should be 100% radiographically...

    Straight seam steel pipe wall thickness control is a difficult production. At present, the straight seam steel pipe manufacturers to improve the wall thickness in the production of precision uses the methods generally including:     1, Tube heating     Heating to the average to prevent rapid up and down temperature. Each take-off and landing temperature is to maintain a smooth slow, the maximum rise and fall temperature does not exceed 30 ℃.     2, Rolling mill mandrel     Average wall thickness of thick wall tube and solid billet make the probability of mandrel bending deformation significantly reduced, can effectively improve the wall thickness of the precision.     3, The accuracy of mandrel     The outer core of the machining accuracy control in ± 0.1mm, mandrel straightness bias does not exceed 5mm. Welding, the two core rods between the piercing a finishing pin positioning, welding in order to...