At present, there are more and more types of straight seam steel pipes. With the rapid development of continuous strip rolling production and the advancement of welding and inspection technology, the welds are constantly improving, the varieties and specifications of welded steel pipes are increasing day by day, and the steel products are also increasing. Hot-rolled round Steel specifications are 5.5-250 mm. Among them: small round steel with a diameter of 5.5-25 mm is mostly supplied in straight strips and bundles and is commonly used as steel bars, bolts, and various mechanical parts; round steel larger than 25 mm is mainly used for manufacturing mechanical parts or seamless steel tube blanks.
For the correct operation of straight seam steel pipes, please refer to the following steps:
1. When lifting straight seam steel pipes, the wire rope is not allowed to be pulled diagonally to prevent the wire rope from coming out of the groove.
2. Pay attention to personal safety and equipment during operation.
3. Always check the switches on the front and rear of the trolley and whether the switch for the maximum hook lifting limit is sensitive.
4. Lubricating points such as straight-seam steel pipe gears, sprockets, chains, and ropes must be lubricated regularly.
5. When operating the cantilever crane, you must cooperate closely with the hanging personnel and obey the hanging instructions.
6. The hook should be fully hung with the coil.
7. The wire rope should be replaced when 10% of its strands are broken.
8. Always check whether the hook lifting brake is easy to operate and sensitive.
9. When lifting the steel coil of the straight seam steel pipe, it should be lifted and lowered gently, and the operation should be steady, accurate, and light.
Straight seam steel pipe welding skills:
1. Check whether the specifications of welding wire and flux are correct according to the welding process regulations to prevent welding accidents caused by incorrect use of welding wire and flux.
2. Supervise the welding environment. When the welding environment is not good (temperature below 0°C, relative humidity above 90%), corresponding measures should be taken before welding.
3. Before pre-welding, check the groove dimensions, including gaps, blunt edges, angles, and staggered edges, to see if they meet the process requirements.
4. Whether the process parameters such as welding current, welding voltage, and welding speed selected during the submerged arc automatic internal and external welding process are correct.
5. Supervise welding personnel to make full use of the length of the arc ignition plate at the end of the steel pipe during automatic submerged arc internal and external welding, and enhance the efficiency of the arc ignition plate during internal and external welding, which will help improve pipe end welding.
6. Supervise the welding personnel to see whether the slag has been cleaned first, whether the joints have been processed, and whether there are oil, rust, slag, water, paint, and other contaminants at the groove during repair welding.
Acceptance method of straight seam steel pipe:
1. The inspection and acceptance of straight seam steel pipes should be carried out by the supplier’s technical supervision department.
2. The supplier guarantees that the delivered straight seam steel pipes meet the requirements of corresponding product standards. The purchaser has the right to inspect and accept products according to corresponding product standards.
3. Straight seam steel pipes should be submitted for acceptance in batches, and the batching rules should comply with the provisions of the corresponding product standards.
4. The inspection items, sampling quantity, sampling locations, and test methods of straight seam steel pipes shall be by the provisions of the corresponding product standards.
5. When the straight-seam steel pipe test results show that a certain item does not meet the requirements of the product standard, the unqualified ones should be singled out, and double the number of samples should be taken from the same batch of straight-seam steel pipes to test the unqualified items. recheck.
ERW high-frequency straight seam steel pipes use hot-rolled coils as raw materials, and the wall thickness can be uniformly controlled at about ±0.2mm. Both ends of the steel pipe are trimmed according to APl standards or GB/T9711.1 standards, the ends are beveled and the length is fixed. Goods and other advantages. In recent years, various gas pipeline network projects and gas companies have widely adopted ERW steel pipes as the main steel pipes in urban pipeline networks. At present, ERW high-frequency straight seam steel pipes account for 60% of the world’s steel pipe usage. Straight seam steel pipe refers to a welded steel pipe with one longitudinal weld seam in the pipe body. GB/9711.1 stipulates that when the diameter is greater than 914.4, the straight seam steel pipe can have two straight welds, and the angle between the welds is 180 degrees. The welding seam requires the same technical parameters as the straight seam steel pipe for the same welding seam.
According to the production process, it is divided into: ERW high-frequency straight seam steel pipe, JCOE straight seam steel pipe, and rolled straight seam steel pipe. Straight seam steel pipe is a general term for production process products such as high-frequency straight seam, submerged arc straight seam, electric welding straight seam, and pipeline straight seam. High-frequency straight seam steel pipe uses the skin effect of high-frequency current to generate high temperature at both ends of the steel plate in a short time and squeeze and fuse them with external force. It is a true base metal butt without a welding rod. Straight seam steel pipe in Hebei often refers to the double-sided submerged arc straight seam steel pipe produced by JCOE. It adopts the JCOE cold-forming process. The welding seam uses welding wire and granular flux is used to submerge the arc at the same time, so it is called submerged arc straight seam steel pipe.
Post time: Jan-26-2024