Large diameter spiral tube production process
(1) The raw materials are strip coils, welding wires, and flux. Strict physical and chemical testing is required prior to input.
(2) The steel head and the tail are butt jointed, and single or double-line submerged arc welding is adopted. After the steel pipe is rolled, automatic submerged arc welding is adopted.
(3) Surface cleaning and pre-bending treatment are carried out by leveling, trimming the edges, and trimming the strips prior to forming.
(4) The electric contact pressure gauge is used to control the cylinder pressure on both sides of the conveyor to ensure the smooth conveying of the conveyor belt.
(5) Externally controlled or internally controlled roll forming.
(6) Weld control device is used to ensure that the weld meets the welding requirements, strictly control the pipe diameter, the misalignment and the weld gap.
(7) Both internal and external welding are performed by single or double wire submerged arc welding, using a Lincoln welding machine in the United States to obtain stable welding specifications.
(8) The welds are in-line continuous ultrasonic automatic injury inspection to ensure non-destructive testing of 100% spiral welds. If there is a defect, the alarm will automatically alarm and spray, and the production worker can adjust the process parameters at any time to eliminate defects.
(9) The steel pipe is cut into a single piece by an air plasma cutting machine.
(10) After cutting into a single steel pipe, the first three inspections of each batch of steel pipes shall be inspected in accordance with the first inspection system for mechanical properties, chemical composition, fusion state, surface quality and non-destructive testing to ensure the pipe making process. . Once qualified, it can be formally put into production.
(11) The part of the weld with the continuous acoustic flaw detection mark, after manual ultrasonic and X-ray inspection, if it is defective, the repair will pass the non-destructive test again until it is confirmed.
(12) The butt weld pipe of the strip and the butt joint with the spiral „ slit are checked by X-ray TV or film ã ‚
(13) A hydrostatic pressure test was performed on each of the steel pipes, and the pressure was radially sealed. The test pressure and time are strictly controlled by the steel pipe water pressure microcomputer detection device. Automatically print and record test parameters.
(14) Tube end processing to precisely control the perpendicularity of the end face, groove angle and blunt edge.