1. On the surface, judge, that is, inspection in appearance. The appearance inspection of the welding joint is a simple and widely used inspection method. It is an important part of the inspection of the finished product. It is mainly to find the defects on the surface of the weld and the deviation of the size. Generally, it is observed by the naked eye, and uses standard models, quantitative regulations and magnifying glasses to test. If there is defects on the surface of the weld, there is a possibility of defects inside the weld.
2. Inspection of physical methods: The method of physical testing is to use some physical phenomena to determine or test. The inspection of the internal defects of the materials or workpieces is generally used to use non -destructive detection methods. No damage detection includes ultrasonic detection, ray detection, penetration detection, magnetic detection, etc.
3. Interest test of the pressure container: In addition to the sealing test, the pressure container must also be conducted. There are two types of hydraulic tests and air pressure tests. They can test the denseness of the welds and pipelines working under pressure. The air pressure test is more sensitive and speed than the hydraulic test. At the same time, the product does not need drainage treatment after the test, which is particularly applicable to products with difficulty drainage. However, the danger of the test is greater than the hydraulic test. When testing, we must follow the corresponding security technical measures to prevent accidents during the test.
4. Determine test: Welding containers of storage liquid or gas, non -dense defects of their welds, such as penetrating cracks, stormhole, residue, unproof and loose tissue, etc., can be found with dense tests. The density testing methods include: kerosene test, water load test, water punch test, etc.
5. Each steel tube of quiet water test should do a static water pressure test without leakage. The test pressure is calculated by the test calculation P = 2ST/D. Steel belt standard specifies 60%of the minimum value of yield (Q235 is 235MPa). Stabilization time: D <508 test pressure maintenance time is not less than 5 seconds; D ≥ 508 test pressure maintains no less than 10 seconds 4, non -destructive detection of steel pipe supplement welding seams, steel bands, welded welds and ring seams should be Perform X -ray or ultrasonic inspection. For the spiral welding seams for the steel direction for combustible ordinary fluid transportation, 100%SX rays or ultrasonic inspections shall be performed. The spiral welding seams of steel pipes used in ordinary fluid transportation for water, sewage, air, heating steam should be performed. Ultrasonic inspection spot check (20%).
According to the results of the quality inspection of the spiral steel pipe, the spiral steel pipes are usually divided into three categories: qualified products, repairs and waste products. Qualified products refer to the spiral steel pipes that meet the relevant standards or the technical conditions of the delivery acceptance of the exterior and the internal quality; the repairs refer to the appearance quality and inherent quality of the repairs. Spiral steel pipes; waste refers to the unqualified appearance and inherent quality, and the spiral steel pipes with standards and acceptance conditions are still not allowed to be repaired or repaired.
