Changsha Xiangjia Metal Materical Co., Ltd.

  1.       From the perspective of being suitable for offshore oil and gas transportation, it is bound to focus on the construction of LSAW. With the development of oil exploration to the depths of the ocean, due to the impact of pressure, impact and bending forces on the pipeline laying on the seabed, flattening occurs. In order to improve the pipeline transportation capacity and ensure, the submarine pipelines are developing in the direction of thick walls, so the submarine pipelines mostly use LSAW. 2.       Coal slurry and slurry pipelines need to use LSAW. The pipeline transportation of coal and mineral powder in a "paste" state is the effective upward direction. 3.       LSAW are required for machinery, construction, and chemical engineering. The valve seat of the machinery industry manufactures the valve seat. At present, the inner hole is processed by the forging part, which is time-consuming and costly. If the LSAW is used, it is much more economical. In addition, th

    The base material of  LSAW  is a single controlled-rolled steel sheet isotropic, which can be 100% non-destructive testing. The stress state of LSAW is good after forming. Due to the mechanical expansion, the internal stress can be eliminated and the geometric accuracy of the steel pipe can be improved. The internal quality of LSAW is good. Because welding is performed on a flat surface, welding conditions, automatic tracking, and non-destructive testing are easy to carry out, which results in low weld height and high accuracy of internal and external welds.   LSAW has a wide range of wall thickness, generally 6-25 mm, and the thickness can reach 45 mm.   LSAW has good bending and flattening resistance. LSAW welds are 60% shorter than spiral welded pipes, and the probability of weld defects is low.    Longitudinal seam welded pipe (LSAW) has high reliability.   Changsha Xiangjia Metal Materical Co., Ltd. the Steel Pipe Division of ADTO GROUP, is one of the leading manufacturers of

  Large diameter SSAW steel pipe  is a spiral steel pipe with a diameter greater than 1 meter. It is formed by bending steel strip and then welding. Steel pipes are subjected to water pressure, bending, flattening and other experiments. Usually the delivery length is 12 meters, or customized length. In the production of large-diameter SSAW steel pipes, there are many influencing factors cause to misalignment. Steel pipes are degraded due to misalignment excessive tolerance. What is cause to misalignment how to prevent it? Reasons of misalignment for large-diameter SSAW steel pipes: 1. The sickle bend of the steel belt is the main factor causing the misalignment of the steel pipe. In the forming of SSAW steel pipes, the sickle bend of the steel strip changed the forming angle continuously, resulting in the change of the weld gap, resulting in seams, staggered edges or even overlapping edges, which serious affected the quality of steel pipe. Therefore, pay attention to the sickle bend af

  LSAW steel pipes  shall be subjected to hydraulic test one by one, and the test pressure shall be calculated according to the formula, the maximum pressure shall not exceed 10MPa, and shall be stabilized. The time should be more than 5s, and there should be no leakage on the pipe wall. P=2RS/D(2) In the formula:  P——test pressure, MPa; R——stress, 50% of the yield point, MPa; S——Nominal wall thickness of steel pipe, mm; D——Nominal outer diameter of steel pipe, mm; The supplier can replace the hydraulic test with eddy current flaw detection, and the qualification level should meet the A level in the GB/T 7735-1995 standard. Changsha Xiangjia Metal Materical Co., Ltd.  has been engaged in the  steel pipe industry over 20 years and has now become a leader in the industry. If you have any inquiry, welcome to contact us!

There are three main production processes for polyurethane insulating pipes: "one-step method", "pipe-in-pipe method" and "foam spray method". The "one-step method" is mainly used for steel pipes with a pipe diameter less than DN500. The process is limited with the pipe diameter range: the larger the pipe diameter, the difficulty of forming the insulation layer at one time will increase, and the eccentricity problem will become more serious. . The "pipe-in-pipe method" is suitable for various pipe diameters, and the formation and eccentricity of the insulation layer are easier to control than the "one-step method". However, the process is more complicated, the foam density is uneven, the cavity is large, and it is difficult to make a large diameter outer protective tube. "Foam spraying method" is a new type of process, using foam spraying equipment to spray polyurethane foam on the surface of the steel pipe directly,

 Non-destructive testing for the surface of  LSAW steel pipes : for ferromagnetic steel pipes, should use magnetic particle testing; for non-ferromagnetic steel pipes, should use penetration testing. The application of surface non-destructive testing is carried out in accordance with the requirements of the standard. The detection objects and applications are generally as follows: (1) Quality inspection of the outer surface of pipe. (2) Detection of surface defects of important butt welds. (3) Detection of surface defects of important fillet welds. (4) Detection of surface defects in the welding joints of important socket welding and jumper tee branch pipes. (5) Surface defect detection after pipe bending. (6) Groove detection of welded joints with larger material quenching tendency. (7) Detection of grooves for non-austenitic stainless steel pipes whose design temperature is lower than or equal to -29 degrees Celsius. (8) Double-sided weldments are inspected after root cleaning (9) Wh