SAWH Steel Pipe refers to the use of submerged arc welding process, made of welded steel pipes with spiral seam.
Generally used: welded pipes conveying fluid, metal structures, pile and so on. Our products are widely used in water engineering, petrochemical industry, chemical industry, power industry, agricultural irrigation, urban construction, is one of 20 key product of development. For the transport of liquids: water supply, drainage. For gas transportation: gas, steam, liquefied petroleum gas. For structural purposes: as piling pipe, for bridges; piers, roads, buildings and other structures tube.
Manufacturing process of sawh pipe
(1) raw materials that strip, wire, flux. Go through rigorous physical and chemical testing prior to investment.
(2) strip head and tail docking, single or double wire submerged arc welding, in the rolled steel by automatic submerged arc welding.
(3) before forming the strip after flattening, cutting, trimming, planing, surface cleaning and transportation to the curved side.
(4) the use of electrical contacts on both sides of pressure control conveyor cylinder pressure to ensure the smooth delivery of the strip.
(5) the use of internal or external control roll forming.
(6) with gap control device to ensure that the weld gap to meet the welding requirements, diameter, misalignment and weld gap have been strictly controlled.
(7) within the welding and soldering are used outside the United States Lincoln welding machine for single or double wire submerged arc welding, thereby obtaining a stable welding specifications.
(8) After welding the weld line ultrasonic injury examination was to ensure 100% coverage of non-destructive testing spiral weld. If defects, automatic alarm and spraying tags, production workers and so at any time adjusting the process parameters, and remove defects.
(9) using air plasma cutting machine to cut a single tube.
(10) cut into a single pipe, each batch of steel should be carried out strict inspection system, the mechanical properties of the weld inspection, chemical composition, fusion status, as well as through the steel surface quality NDT inspection to ensure that qualified pipe technology before they can formally put into production.
(11) there is a continuous acoustic testing marks the site of the weld, manual ultrasonic and X-ray review, if there are defects after repair again after destructive testing, until the confirmation of the defect has been eliminated.
(12) strip butt weld, and intersect with spiral weld small joint where the pipe all through the X-ray television or film examination.
(13) each pipe after hydrostatic test pressure radial seal. Test pressure and time by a steel pipe pressure microcomputer detection device is strictly controlled. Test parameters are automatically printed records.
(14) pipe end machining, so that the end vertical slope altercation and accurate control of the blunt edge.
