Spiral steel pipe is a kind of spiral welded steel pipe which is formed by automatic double wire submerged arc welding. The main production process is as follows:
(1) raw materials that is, strip coil, wire, flux. Before being put into use, they must undergo strict physical and chemical tests.
(2) The head and tail connection of the strip steel is welded by single wire or double wire submerged arc welding, and automatic submerged-arc welding is adopted after the steel pipe is rolled.
(3) before forming, the strip is straightened, trimming, planing, surface cleaning, transportation and pre-bending.
(4) the use of electrical pressure gauge to control the conveyor on both sides of the pressure cylinder to ensure the smooth delivery of steel.
(5) the use of external or internal control roller molding.
(6) the welding gap control device is adopted to ensure that the weld gap meets the welding requirement, and the diameter of the pipe, the amount of misalignment and the clearance of the weld are strictly controlled.
(7) Lincoln welding machine is used for single wire or double wire submerged arc welding in inner welding and outer welding, thus obtaining stable welding specification.
(8) the welded seam is checked by the on – line continuous ultrasonic automatic flaw detector, which ensures 100% non – destructive inspection coverage of the spiral seam. If there are defects, automatic alarm and spray marking, production workers at any time to adjust the process parameters, timely elimination of defects.
(9) the use of air plasma cutting machine will be cut into a single pipe.
(10) cut into a single steel pipe, each batch of steel pipe first three to a strict first inspection system, Check the mechanical properties of the weld, chemical composition, the state of fusion, the surface quality of the pipe and the non-destructive inspection to ensure that the pipe making process qualified, before formally put into production.
(11) The parts of the welds marked by continuous acoustic detection shall be rechecked by manual ultrasonic and X-ray, and if there are defects, after repair, shall be subjected to a nondestructive examination again until it is confirmed that the defects have been eliminated.
(12) The pipe where the welding seam of the strip steel and the T-joint intersecting with the spiral weld are all examined by X-ray television or film.
(13) each tube after hydrostatic test, the pressure of radial seal. The test pressure and time are strictly controlled by the microcomputer testing device of steel pipe water pressure. Automatic printing of test parameters.
(14) pipe end machining, so that end verticality, slope angle and blunt edge of the accurate control.
Spiral steel pipe storage tips:
The steady improvement of spiral steel pipe product quality is the strong guarantee of the company’s economic benefits. Over the years, we have insisted on putting product quality in the first place, strengthening quality supervision and information feedback, and controlling quality hidden danger in the process. The passing rate of products in Tianjin’s previous industrial product quality inspection is 100%. High quality products make our company has made the American Petroleum Institute issued a series of API SPEC 5L product certification and other certificates. “This is a major breakthrough for sales staff customers and products to further expand the export market to get an important pass.”
1) keep spiral steel pipe products site or warehouse, should choose in a clean, unobstructed drainage place, away from the production of harmful gas or dust factories and mines. In the field to remove weeds and all debris, keep the steel clean.
2) in the warehouse shall not be with acid, alkali, salt, cement and other corrosive materials stacked together. Different varieties of steel should be stacked separately to prevent confusion and contact corrosion.
3) large section steel, rail, steel plate, large diameter spiral steel pipe, forging can be stacked in the open.
4) small and medium-sized steel, wire, steel, medium caliber steel pipe, steel wire and wire rope, etc., can be stored in a well-ventilated shed, but must be covered under the mat.
5) some small steel, steel plate, steel strip, silicon steel sheet, small caliber or thin-walled spiral steel pipe, all kinds of cold rolled, cold drawn steel and high price, easy to corrode metal products, can be stored in storage.