Spiral steel pipe quality inspection

Spiral steel pipe should be mechanical performance test and flattening test and flaring test before leaving the factory, and must meet the requirements of the standard. The quality inspection method of straight seam steel pipe is as follows:
1, judging from the surface, that is, in appearance inspection. The appearance inspection of welded joints is a simple and widely used inspection method. It is an important part of the inspection of finished products. It mainly finds the defects on the weld surface and the deviation in dimensions. It is usually visually inspected and tested with tools such as standard templates, gauges, and magnifiers. If there is a defect in the surface of the weld, there is a possibility of a flaw inside the weld.
2. Physical method inspection: The physical inspection method is a method that uses some physical phenomena to measure or test. Inspection of defects in materials or workpieces is generally performed by means of non-destructive testing. Non-destructive testing includes ultrasonic testing, ray testing, penetrant testing, and magnetic testing.
3, the strength of the pressure vessel inspection: pressure vessel, in addition to the sealing test, but also for strength testing. There are two kinds of pressure test and pressure test. They all test the tightness of welds in vessels and pipes that work under pressure. The air pressure test is more sensitive and quicker than the water pressure test. At the same time, the product after the test does not need to be drained. It is particularly suitable for products with difficult drainage. However, the test is more dangerous than the hydrostatic test. When carrying out tests, corresponding safety measures must be observed to prevent accidents during the test.
4. Test for compactness: For welding vessels that store liquids or gases, the non-dense weld defects, such as penetrating cracks, pores, slag inclusions, incomplete penetration, and loose structures, can be detected by the compactness test. Denseness test methods include: kerosene test, water load test, water test, etc.
5, hydrostatic test Each pipe should be hydrostatic pressure test without leakage phenomenon, the test pressure is calculated according to the test P = 2ST / D type S-static hydrostatic test test stress Mpa, the test stress of the hydrostatic test corresponding The steel strip standard specifies 60% of the minimum yield (Q235 is 235Mpa). Regulatory time: D <508 test pressure retention time of not less than 5 seconds; D ≥ 508 test pressure retention time of not less than 10 seconds 4 non-destructive testing of steel pipe repair welds, steel-to-head welds and hoop seams should be carried out X-ray or ultrasonic inspection. Spiral welds for the transport of flammable ordinary fluids shall be subjected to 100% SX-ray or ultrasonic inspection. Spiral welds used for steel, such as water, sewage, air, and heating steam, shall be subjected to X-ray or Ultrasonic test checks (20%).
According to the quality inspection results of spiral steel pipes, spiral steel pipes are usually divided into three categories: qualified products, rework products and waste products. Qualified products refer to spiral steel tubes whose appearance quality and internal quality are in compliance with the relevant standards or delivery acceptance technical conditions. Rework products mean that the appearance quality and internal quality do not fully comply with standards and acceptance criteria, but allow repairs, and the standards and acceptance criteria can be met after rework. Spiral steel pipe; waste refers to the appearance of quality and internal quality failure, does not allow repair or repair after still failed to meet the standards and acceptance conditions of spiral steel pipe.
Waste products are divided into internal waste and external waste. Internal waste refers to the scrap spiral steel pipe found in the foundry or in the foundry; external waste refers to the scrap found after the delivery of the spiral steel pipe, usually revealed during machining, heat treatment, or use, resulting in far-reaching economic losses. Than within the waste. In order to reduce external waste, the batch production of spiral steel pipes is best sampled before the factory for experimental heat treatment and rough processing, as far as possible in the spiral steel pipe plant to find potential spiral steel pipe defects in order to take the necessary remedial instructions.
Tianjin Baoshun Chengcheng Steel Pipe Co., Ltd. is a leading large-scale enterprise specializing in the production of spiral steel pipes. It is located in the beautiful port city of Tianjin, producing double-sided submerged arc spiral welded steel pipes with φ219-φ1820 (wall thickness 5mm-18mm).
Contact Tel: 13672313311 Contact: Yang Tai