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How to Detect the Quality of Spiral Steel Pipe

Date:2018-02-28    View:781      Tag:How to Detect the Quality of Spiral Steel Pipe
Spiral pipe factory should be carried out before the mechanical properties test and flattening test, and the flaring test, to meet the standards. Spiral pipe quality inspection methods are as follows:
1, on the surface, that is visual inspection. Visual inspection of welded joints is a straightforward process, but widely used test methods are an important part of product testing with major defects and variations on the surface of the welded dimension. Usually with the naked eye, using standard models, gauges and test tools, such as magnifying glass. If the weld surface defects, weld defects may exist inside.


2, physical test methods: physical test method is to use some physical phenomena to test or test methods. Or in the workpiece material defect inspection, the general nondestructive testing methods. Non-destructive testing, radiation detection, penetration testing, magnetic testing.


3, pressure vessel strength test: pressure vessel, in addition to rigorous testing, but also for strength test. Common two kinds of hydraulic test and pressure test. They can be pressure vessel and pipe welding tightness test. Hydrostatic test is more sensitive than test speed, and the product is not treated with waste water after the test. The drainage problem is especially applicable to the product. But the risk is greater than the test pressure test. During testing, appropriate safety precautions must be followed to prevent accidents during the test.


4, compact test: liquid or gas tank welding, the weld is not dense defects, such as penetrating cracks, porosity, slag, incomplete penetration of loose tissue, etc., can be used for density testing. Compaction test methods are: kerosene test, water test, water hammer test.


5, hydrostatic test should be done without leakage of pipeline hydrostatic test, hydraulic test pressure calculation P = second / DS - hydraulic test stress test, hydraulic test stress test, according to the corresponding steel standard minimum output Degree (Q235 235mpa) choice 60%. Regulatory authorities: D <508 Test pressure to maintain time of not less than 5 seconds; D ≥ 508 Test pressure to maintain time of not less than 10 seconds 4, non-destructive testing of steel welds, weld girth should be taken with the end of the X-ray or ultrasonic inspection. Common combustible fluid delivery Spiral welded pipe should be 100% ray or ultrasonic testing of SX for water, sewage, air, steam and other general transmission fluid spiral welded steel pipe X-ray or ultrasonic inspection (20%) should be checked.


Spiral pipe quality test results, spiral pipe generally divided into three categories: qualified, rework and scrapped. Qualified means to meet the standard or technical delivery and acceptance conditions of the inner quality of the spiral pipe quality and appearance; Rework refers to the quality of the inner and outer appearance of the quality does not fully meet the acceptance criteria and the body, but allows the repair and repair to meet the standards and Acceptance conditions of the spiral tube; waste refers to the unqualified quality and appearance of the inner quality of the spiral steel still does not meet the standards and acceptance conditions do not allow repair or rework.

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