Φ720*8mm Spiral steel pipe

 

 

Spiral steel pipe is the raw material of strip coil, often temperature extrusion molding, automatic double-wire double submerged arc welding process made of spiral seam pipe.

 

(1) raw materials that coil, wire, flux. In the input before going through rigorous physical and chemical tests.

 

(2) head-to-tail docking, the use of single-wire or double-wire submerged arc welding, rolled into steel after the adoption of automatic submerged arc welding.

 

(3) Before forming, the strip after the flattening, cutting edge, planing, surface cleaning and transportation to the bending treatment.

 

(4) the use of electrical contact pressure gauge control the pressure on both sides of the conveyor cylinder pressure to ensure the smooth transport of strip.

 

(5) the use of external control or internal control roller molding.

 

(6) the use of weld gap control device to ensure that the welding gap to meet the welding requirements, diameter, the wrong amount of margin and weld gap are strictly controlled.

 

(7) within the welding and welding are used in the United States Lincoln welding machine for single or double wire submerged arc welding, in order to obtain a stable welding specification.

 

(8) Welded welds have been through the line of continuous automatic ultrasonic inspection instrument to ensure that the 100% of the spiral weld nondestructive testing coverage. If there are defects, automatic alarm and spray marking, production workers at any time to adjust the process parameters, the timely elimination of defects.

 

(9) the use of air plasma cutting machine will cut into single pipe.

 

(10) cut into a single pipe, each batch of pipe must be strict first inspection system to check the mechanical properties of weld, chemical composition, melting conditions, steel pipe surface quality and non-destructive testing to ensure that the pipe process qualified , Can be formally put into production.

 

(11) The location of the weld on the continuous acoustic flaw detection mark, after manual ultrasonic and X-ray review, if there are defects, after repair, again after non-destructive testing until the defects have been eliminated.

 

(12) The welds of the strip butt welds and the pipes of the d-type joints intersecting the spiral welds are all examined by X-ray television or film inspection.

 

(13) Each pipe is subjected to a hydrostatic test, and the pressure is radially sealed. Test pressure and time by the computer control of water pressure microcomputer control. Test parameters automatically print records.

 

(14) pipe end machining, the end of the vertical, groove angle and blunt edge be accurately controlled.