Spiral steel pipe is a spiral steel pipe welded by active double-wire double-sided submerged arc welding process with strip steel coil as raw material, kneading and forming at regular temperature. The production process is as follows: raw materials, i.e. strip steel coil, welding wire, welding flux. In the input before are subjected to severe physical and chemical testing. Strip head and tail butt, the choice of single or double-wire submerged arc welding, in the roll into a steel pipe after the choice of active submerged arc welding spiral steel pipe plant.
Before forming spiral steel pipe plant, the strip through the leveling, cutting edge, planing edge, the appearance of finishing transport and to bend edge processing. Electric contact pressure gauge is selected to control the pressure of the press cylinder at both ends of the conveyor, which ensures the smooth transportation of the strip steel. External control or internal control roll forming is selected. Weld gap control equipment is selected to ensure that the weld gap is satisfied with the welding requirements, pipe diameter, the amount of misalignment and weld gap are strictly controlled.
Production process of spiral steel pipe plant
Both internal and external welding are selected by electric welding machine for single or double wire submerged arc welding, and then obtain stable welding standard. The welded seam is checked by online ultrasonic active flaw meter, which ensures 100 percent nondestructive testing coverage of the spiral weld. If there is a shortcoming, the active alarm and spraying symbols, production workers according to this at any time to adjust the process parameters, timely elimination of shortcomings. The choice of air plasma cutting machine will be cut into a single spiral steel pipe plant.
Cut into a single steel pipe, the first three of each batch of steel pipe to carry out a strict * inspection guidelines to check the mechanical properties of the weld, chemical composition, dissolution, steel pipe appearance quality and through nondestructive flaw detection inspection to ensure that the pipe making process qualified, before officially put into production. Weld seam with successive sonic flaw detection symbols on the part, through manual ultrasonic and X-ray review, such as indeed there are shortcomings, through repair, again through nondestructive testing, until the recognition of shortcomings have been eliminated spiral steel pipe plant.
Strip steel butt weld seam and the location of the spiral weld intersected with the Ding-type joints of the pipe, all through X-ray television or film view, each steel pipe through the hydrostatic test, the pressure is selected radial seal. Experimental pressure and time are strictly controlled by the steel pipe water pressure microcomputer testing equipment. The experimental parameters are actively printed and recorded. Pipe end mechanical processing, so that the end straightness, bevel angle and blunt edge control spiral steel pipe plant.