Spiral steel pipe
is a spiral seam steel pipe made of strip steel coil as raw material, extruded at constant temperature, and welded by automatic double-wire double-sided submerged arc welding process. The main production process is as follows:
(1) The raw materials are steel strip coil, welding wire and flux. They must undergo strict physical and chemical inspections before being put into use.
(2) For the head-to-tail butt joint of the steel strip, single-wire or double-wire submerged arc welding is used, and automatic submerged arc welding is used for repair welding after being rolled into a steel pipe.
(3) Before forming, the strip steel undergoes leveling, trimming, planing, surface cleaning, transportation and pre-bending.
(4) Electrically connected pressure gauges are used to control the pressure of the pressing cylinders on both sides of the conveyor, ensuring smooth conveying 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 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 are 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 steel strip butt welds and the pipes where the T-shaped joints intersect with the spiral welds are all inspected by X-ray television or film.
(13) Each steel pipe has been tested by hydrostatic pressure, 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 verticality, bevel angle and blunt edge of the end face.
Spiral steel pipe storage tips:
The stable improvement of the quality of spiral steel pipe products is a strong guarantee for the improvement of the company's economic benefits. Over the years, we have insisted on putting product quality first, strengthening quality supervision and information feedback, and controlling quality hazards in the process. Our products have a 100% pass rate in all previous industrial product quality inspections in Tianjin. The high-quality products have enabled our company to obtain a series of certificates such as APISPEC5L product certification issued by the American Petroleum Institute. "This gives sales staff an important pass to break through major customers and further expand the export market for their products."
1) The site or warehouse where spiral steel pipe products are stored should be located in a clean and well-drained place, away from factories and mines that produce harmful gases or dust. Weeds and all debris should be removed from the site and the steel should be kept clean.
2) They must not be stacked together with acid, alkali, salt, cement and other materials that are corrosive to steel in the warehouse. Different types of steel should be stacked separately to prevent confusion and contact corrosion.
3) Large steel sections, rails, steel plates, large-diameter spiral steel pipes, forgings, etc. can be stacked in the open air.
4) Small and medium-sized steel, wire rods, steel bars, medium-diameter steel pipes, steel wires and steel wire ropes, etc., can be stored in a well-ventilated material shed, but must be covered with a thatch.
5) Some small steel products, thin steel plates, steel strips, silicon steel sheets, small diameter or thin-walled spiral steel pipes, various cold-rolled and cold-drawn steel products, and high-priced and corrosive metal products can be stored in the warehouse.