The inspection of SSAW steel pipes shall be carried out by the Technical Quality Supervision Department of the supplier. It is necessary for the supplier to ensure that the delivered SSAW steel pipe conforms to the rules of the corresponding product specifications. Purchasers have right to check and inspect according to the corresponding product specifications. SSAW steel pipes shall be submitted for inspection in batches, and the rules for group approval shall conform to the rules of the corresponding product specifications. The inspection items, sample quantity, sampe locations and experimental methods of SSAW steel pipes shall be in accordance with the rules of the corresponding product specifications. With the approval of the buyer, the spiral welded pipe can be sampled in batches according to the rolling root array.
1. Visual inspection
The visual inspection of the SSAW steel pipe is a broad application of abbreviated and inspection methods. It is an important part of product inspection, shortcomings and errors, mainly found on the surface of the weld specification. Generally pass the naked eye, and standard model, surface and inspection tools, such as magnifying glass. If the surface of the weld is defective, the welding defect may be internal.
2. Physical inspection methods
The inspection method is to use the detected physical phenomenon or some physical inspection methods. The shortcomings of the internal SSAW steel pipe inspection in the material or operation are generally selected by non-destructive testing methods. Non-destructive testing, ultrasonic testing, radiation testing, penetration testing, magnetic particle testing, etc.
3. Hydraulic pressure test specification of SSAW steel pipe
There should be no leakage to achieve the hydraulic test of each pipeline, according to the experimental pressure experimental pressure Mpa S-hydrostatic pressure test, the experimental pressure check to calculate P=2ST/D, during which the hydraulic pressure test is in accordance with the smaller yield of the corresponding rules Strip steel (Q235 is 235Mpa), 60% of people choose. Pressure stabilization time: D<508 The pressure test time is less than 5 seconds, D≥508 Check the steel pipe welding seam of the pressure holding time less than 10 seconds, the non-destructive testing of the steel head and girth weld 4 should be X-ray or ultrasonic inspection. For general flammable fluids transported to spiral seam steel pipes should be 100% SX-ray or ultrasonic inspection, used for water, sewage, air, steam, etc. General heating fluid transport pipeline spiral welds should be X-ray or ultrasonic inspection (20% ).
4. Strength experiment of SSAW steel pipe
In addition to the air tightness test, the SSAW steel pipe also has strength test. There are two common inspections and spiral pressure test. They can check the tightness of welding seams of containers and pipes under pressure. Hydrostatic pressure inspection is more flexible than inspection and speed, but after the inspection product has no wastewater treatment, products with difficult drainage are particularly suitable. But the risk is greater than the hydraulic pressure experiment. During the inspection, it is necessary to fit the corresponding technical methods to avoid the occurrence of incidents during the inspection.
5. Compact experiment: liquid or gas maintenance welding, which is not close to welding defects, such as penetration cracks, pores, slag inclusions Storage containers, impervious and loose arrangements, etc., can be used to test the density of the experiment. The dense inspection methods are: kerosene experiment, ballast water experiment, flushing experiment.
