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The spiral steel pipe shall be subjected to mechanical property test, flattening test and flattening test before leaving the factory, and shall meet the requirements of the standard.
1. Judging from the surface, it is also in appearance inspection: the appearance inspection of the welded joint is a simple and widely used inspection method. It is an important part of the inspection of the finished products, mainly to find the defects on the weld surface and the deviation in the size. Through naked eye observation, with standard sample, gauge and magnifying glass and other tools for inspection. If there are defects on the weld surface, there may be defects in the weld.
2. Testing physical methods: physical testing is a method of testing or testing with some physical phenomena. Inspection of internal defects of materials or workpieces is usually done by NDT. NDT includes ultrasonic flaw detection, radiographic inspection, penetrant flaw detection and magnetic flaw detection.
3. Strength test of pressure vessels: pressure vessels should be subjected to strength test besides sealing test. There are two kinds of water pressure test and air pressure test. They can check the weld density of vessels and pipes working under pressure. The air pressure test is more sensitive and faster than the water pressure test, and the test products do not need drainage treatment, especially for the products with difficult drainage. But the risk of the test is larger than that of water pressure test. In the course of testing, safety technical measures must be followed to prevent accidents during the test.
4. Densification test: the welding container for storing liquid or gas, the undense defects of its weld, such as penetrating cracks, pores, slag, unsoldering and loose tissue, can be found by compactness test. The compactness test methods include kerosene test, water carrying test and water impact test.
5、静水试验：每根钢管应做静水压试验而无渗漏现象，试验压力按下试计算 P=2ST/D 式中S—静水压试验的试验应力Mpa，静水试验的试验应力按相应钢带标准规定屈服度最小值（Q235为235Mpa）的60%选取。 稳压时间：D<508试验压力保持时间不少于5秒； D≥508试验压力保持时间不少于10秒 4 无损检测 钢管的补焊焊缝、钢带对头焊缝及环向缝应进行X射线或超声波检验。对于可燃普通流体输送用的钢向的螺旋焊缝应进行100%SX射线或超声波检验，对用于水、污水、空气、采暖蒸汽等普通流体输送用的钢管的螺旋焊缝应进行X射线或超声波检验抽查（20%）。
5, static water test: each steel pipe should be static water pressure test without leakage, test pressure is pressed to calculate the test stress Mpa in P=2ST/D S static water pressure test, and the test stress of static water test is selected according to the minimum yield of the corresponding steel band standard (Q235 235Mpa). Steady pressure time: D<508 test pressure retention time not less than 5 seconds; D > 508 test pressure retention time not less than 10 seconds 4 nondestructive testing of steel pipe weld seam, steel strip to the head weld and circumferential seam should be X ray or ultrasonic inspection. 100%SX - ray or ultrasonic inspection should be carried out for the spiral welds used for the transport of flammable ordinary fluids. The spiral welds of steel pipes used for ordinary fluid transportation, such as water, sewage, air, heating steam, etc., should be examined by X ray or ultrasonic inspection (20%).