What is the production technology of spiral welded steel pipe

(1) Raw materials are strip steel, welding wire and flux. Before putting into operation, they must pass strict physical and chemical tests.
(2) Single or double wire submerged arc welding shall be adopted for butt joint of strip steel head and tail, and automatic submerged arc welding shall be adopted for repair welding after rolling steel pipe.
(3) Before forming, the strip steel is leveled, cut and planed, and the surface is cleaned, transported and pre bent.
(4) The electric contact pressure gauge is used to control the pressure of the oil cylinder on both sides of the conveyor to ensure the smooth transportation of the strip steel.
(5) Adopt external control or internal control roll forming.
(6) The gap control device is used to ensure that the gap meets the welding requirements, and the pipe diameter, stagger and gap are strictly controlled.
(7) Both internal and external welding are carried out by single wire or double wire submerged arc welding with Lincoln Electric welding machine, so as to obtain stable welding quality.
(8) All the welded joints have been inspected by on-line continuous ultrasonic automatic damage instrument, which ensures 100% coverage of non-destructive testing of spiral welds. If there is any defect, it will automatically alarm and spray the mark, and the production workers will adjust the process parameters at any time to eliminate the defect in time.
(9) The spiral welded steel pipe is cut into single pieces by air plasma cutting machine.
(10) After cutting into single steel pipe, each batch of the spiral welded steel pipe shall be subject to strict first inspection system, and the mechanical properties, chemical composition, fusion status, surface quality of steel pipe and non-destructive testing shall be inspected to ensure that the pipe manufacturing process is qualified before it is put into production.
(11) After manual ultrasonic and X-ray recheck, if there is any defect on the part with continuous acoustic flaw detection mark on the weld, after repair, it shall be subject to non-destructive inspection again until it is confirmed that the defect has been eliminated.
(12) The pipe of butt weld of strip steel and T-joint intersecting with spiral weld shall be inspected by X-ray television or film.