Introduction To Spiral Steel Pipe Production Process And Its Classification Standards

Spiral steel pipe production process: It is a spiral seam steel pipe welded by automatic double-wire double-sided submerged arc welding process using strip steel coil plate as raw material, constant temperature extrusion molding.

(1) Raw materials include steel strip coil, welding wire, and flux. They must undergo strict physical and chemical inspections before being put into use.

(2) The head and tail of the steel strip are butt-jointed using single-wire or double-wire submerged arc welding. After being rolled into a steel pipe, automatic submerged arc welding is used for repair welding.

(3) Before forming, the strip steel is leveled, trimmed, planed, surface cleaned, transported, and pre-bent.

(4) Electric contact pressure gauges are used to control the pressure of the cylinders on both sides of the conveyor to ensure smooth transportation of the strip.

(5) Adopt external control or internal control roller forming.

(6) A weld gap control device is used to ensure that the weld gap meets the welding requirements. The pipe diameter, offset amount, and weld gap are all strictly controlled.

(7) Both internal and external welding use American Lincoln welding machines for single-wire or double-wire submerged arc welding to obtain stable welding specifications.

(8) All completed welds have been inspected by an online continuous ultrasonic automatic flaw detector, ensuring 100% non-destructive testing coverage of spiral welds. If there is a defect, it will automatically alarm and spray mark, so that production workers can adjust the process parameters at any time to eliminate defects in time.

(9) Use an air plasma cutting machine to cut the steel pipe into individual pieces.

(10) After cutting into individual steel pipes, the first three steel pipes in each batch must undergo a strict first inspection system to check the mechanical properties, chemical composition, fusion status of the welds, the surface quality of the steel pipes, and non-destructive testing to ensure the pipe making process Only after passing the test can it be officially put into production.

(11) The areas with continuous sonic flaw detection marks on the welds will undergo manual ultrasonic and X-ray re-examination. If there are indeed defects, they will be repaired and then undergo non-destructive inspection again until it is confirmed that the defects have been eliminated.

(12) The pipes where the strip butt welds and the T-shaped joints intersecting the spiral welds are located must be inspected by X-ray television or film.

(13) Each steel pipe has undergone a hydrostatic pressure test, and the pressure is radially sealed. The test pressure and time are strictly controlled by the steel pipe water pressure microcomputer detection device. Test parameters are automatically printed and recorded.

(14) The pipe end is machined to accurately control the end face verticality, bevel angle, and blunt edge.

Spiral steel pipes and their standard classifications: Spiral seam submerged arc welded steel pipe SY5036-83 for pressure-bearing fluid transportation is mainly used for pipelines transporting oil and natural gas; Spiral seam high-frequency welded steel pipe SY5038-83 for pressure-bearing fluid transportation is used for high-frequency welding. Spiral seam high-frequency welded steel pipes used for pressure fluid transportation, welded by welding method. The steel pipe has strong pressure-bearing capacity, good plasticity, and is easy to weld and process. The spiral submerged arc welded steel pipe SY5037-83 is generally used for low-pressure fluid transportation. It is made by double-sided automatic submerged arc welding or single-sided welding and is used for water, gas, and Submerged arc welded steel pipes for general low-pressure fluid transportation such as air and steam