The
ssaw steel pipe shall be the first to be in the performance test, the flattening test and flare test before leaving the factory, and shall meet the requirements specified in the standard.
Physical method testing: The physical testing method is a method of measuring or testing using some physical phenomena. Inspection of the internal defects of materials or workpieces is generally carried out by means of non-destructive testing. Non-destructive testing includes ultrasonic flaw detection, The singularity of the surface, that is, in the appearance inspection. The appearance inspection of the welded joints is a simple and widely used inspection method. It is an important part of the inspection of finished products In the case of the thin and is a possibility of defects inside the weld.
Non-destructive testing, repair welding of steel pipes, steel-to-head welds and hoop seams shall bet to X-ray or ultrasonic inspection. For the spiral weld of the steel direction for the transportation of combustible ordinary fluids, 100% SX Ray- ultrasonics shall be carried out. X-rays shall be applied to the spiral welds of steel pipes used for the transportation of common fluids such as water, sewage, air and heating steam.
The strength test of pressurized containers: In addition to the sealing test, the pressure vessel of the fluid tests and air pressure tests. There are two types of hydraulic tests and air pressure tests. The air pressure test is more sensitive and speedy than the water pressure test. At the same time, the tested product does not need to be drained, which is especially suitable for products with difficult drainage. The conducting test, the corresponding safety technical measures must be observed to prevent accidents during the test.
Density test: In the case of a welded container for storing liquid or gas, the indentation of the weld is not dense, such as penetrating cracks, pores, slag inclusions, incomplete penetration and loose structure, etc., which can be found by a compactness test. The methods of compactness test include: kerosene test, water carrying test, water flushing test, etc.
The hydrostatic test requires that each steel pipe should be hydrostatically tested without leakage. The test pressure is calculated according to the test: P=2ST/D, the test stress Mpa of the S-hydrostatic test, and the test stress of the hydrostatic test should be corresponding steel strip standard specifies 60% of the minimum yield (Q235 is 235Mpa). Regulating time: D<508 test pressure holding time is not less than 5 seconds; D≥508 test pressure holding time is not less than 10 seconds.
