q235b carbon welded seamless ms spiral welded steel pipe

(1) raw materials are steel coil, wire and flux. Strict physical and chemical tests should be carried out before the input.
(2) the connection of steel head and tail is made of single wire or double wire submerged arc welding. After rolling into steel pipe, automatic submerged arc welding is applied.
(3) before forming, strip steel is leveled, trimming and planing, surface cleaning and transportation and bending edge treatment.
(4) the electric contact pressure gauge is used to control the pressure of the two sides of the conveyor under the pressure of the cylinder, so as to ensure the smooth conveying of the strip.
(5) use external or internal control roll forming.
(6) the weld gap control device is adopted to ensure that the weld gap meets the welding requirements, and the pipe diameter, the wrong side quantity and the weld clearance are strictly controlled.
(7) Lincoln welder is used for internal and external welding to carry out single wire or double wire submerged arc welding, so as to achieve stable welding specifications.
(8) the welded seam after welding is checked by online continuous ultrasonic automatic injury instrument, which ensures 100% of the spiral welded seam's NDT coverage. If defective, automatic alarm and spray mark, production workers adjust process parameters at any time, eliminate defects in time.
(9) use air plasma cutting machine to cut the steel pipe into single root.
(10) after cutting into single steel pipe, each steel pipe must be strictly first inspected, to check the mechanical properties of the weld, the chemical composition, the condition of dissolution, the quality of the surface of the steel tube and the inspection of nondestructive testing, so as to ensure that the production of the pipe is qualified.
(11) the spot on the welding seam with continuous sound wave flaw detection, after the manual ultrasonic and X ray examination, if the defect is true, after the repair, again after the nondestructive test, until the confirmation defect has been eliminated.
(12) all the butt welded joints of the strip and the joint of the butt joint with the spiral weld are all examined by X ray television or radiography.
(13) every steel pipe is hydrostatic pressure test, and the radial seal is adopted for the pressure. The test pressure and time are strictly controlled by the microcomputer inspection device for steel pipe water pressure. The test parameters are automatically printed and recorded.
(14) pipe end machining, so that the verticality of ends, slope angles and blunt edges can be accurately controlled.