Spiral steel pipe is a steel coil plate as raw material, often warm extrusion molding, automatic double-wire double-sided submerged arc welding process into the spiral seam pipe.
Here is a brief introduction to the production process of spiral steel pipe: Raw material namely strip coil, wire, flux.
Before the input must undergo rigorous physical and chemical tests.
Steel head and tail docking, the use of single wire or double wire submerged arc welding, after the coil into the steel pipe with automatic submerged arc welding repair.
Before forming, the strip has been leveling, trimming, trimming, surface cleaning and conveying and bending.
Using the electric contact pressure gauge to control the pressure of the oil cylinder on both sides of the conveyor ensures the smooth conveying of the strip.
The use of external control or internal control roll molding.
The welding seam clearance control device is used to ensure that the weld clearance meets the requirements, the pipe diameter, the wrong edge quantity and the weld clearance are strictly controlled.
Both internal and external welding using the United States Lincoln Welding machine for single or double wire submerged arc welding, so as to obtain a stable welding quality. The welded welds are inspected by the on-line continuous ultrasonic automatic injury instrument, which guarantees the NDT coverage of 100% of the spiral welds.
If there are defects, automatic alarm and spraying mark, the production workers adjust the process parameters at any time, eliminate defects in time.
The use of air plasma cutting machine to cut a single root steel pipe.
Cut into a single steel pipe, each batch of steel pipe to carry out a strict first inspection system, check the mechanical properties of the weld, chemical composition, fusion status, the surface quality of steel pipe and through nondestructive testing, to ensure that the pipe process qualified to be formally put into production.
The weld has continuous sonic flaw marks on the site, after manual ultrasound and X-ray review, if there is a defect, after repair, again through non-destructive testing, until the identification of the defect has been eliminated.
The tube of the steel butt weld and the ding-type joint which intersects with the spiral weld is checked by X-ray television or film. After each steel tube hydrostatic test, the pressure adopts radial seal. The test pressure and time are strictly controlled by the steel tube hydraulic pressure microcomputer detecting device.
Test parameters automatically print records. The pipe end is machined so that the end face verticality, slope angle and blunt edge are accurately controlled.