The
piling pipe is a kind of spiral seam steel pipe, which is made of steel strip coil as raw material, often warm extrusion molding, and automatic double wire submerged arc welding process
(1) raw material, i.e., steel coil, wire and flux, must pass through the strict physical and chemical inspection before the investment. (2) the butt welding of the steel strip is made of single wire or double wire submerged arc welding
(3) before forming, the steel strip after leveling, trimming, planing, surface cleaning and conveying and bending edge treatment. (4) the use of electric contact pressure gauge to control the pressure on both sides of the conveyor cylinder, to ensure the smooth delivery of steel strip
(5) external control or internal control roll forming
(6) the use of weld gap control device to ensure that the weld gap to meet the requirements of welding, pipe diameter, the amount of edge and weld clearance are strictly controlled
(7) both internal and external welding are carried out by single wire or double wire submerged arc welding in the United States
(8) weld after continuous on-line automatic ultrasonic inspection instrument injury, to ensure coverage of spiral weld NDT 100%. If defective, automatic alarm and spray marking, production workers and adjust process parameters, timely elimination of defects.
(9) the air plasma cutting machine is used to cut the steel pipe into a single unit
(10) into a single tube, each batch of steel pipe should be carried out strict inspection system first, chemical composition and mechanical properties of weld, inspection, blending, surface quality of piling pipe as well as a nondestructive inspection, to ensure that the process of good control, can be formally put into production.
(11) acoustic detection for weld mark the site, after manual ultrasonic and X ray review, if there are defects, after repair, again after testing, until the defects have been eliminated. (12) and strip butt weld D intersects with spiral weld joint in the tube, after all X ray TV or check the film.
(13) each steel pipe has been tested by hydrostatic pressure, and the pressure is controlled by the radial seal. The test pressure and time are strictly controlled by the hydraulic pressure testing device.
(14) pipe end machining, so that the end face verticality, slope angle and blunt edges are accurately controlled.
