Nowadays, in our daily life, the use of pipelines is indispensable, because all kinds of daily resources require pipelines as carriers, and in many pipelines, straight seam welded pipes have moderate comprehensive properties and strength due to moderate carbon content. The properties of plasticity and welding are well matched, so it is the most widely used.
According to the straight seam welded pipe, according to the rules of GBT3091-2001 "welding welded pipe for low-pressure fluid transportation", the appearance quality of the welded pipe should be lubricated, and defects such as folding, cracking, delamination and lap joint are not allowed. Committed to the surface of the pipe does not exceed the negative wall thickness of the scratches, scratches, joint dislocation, burns and scars. Welding thickness and welding ribs.
Straight seam pipes should be subjected to mechanical performance tests and flattening experiments as well as flaring experiments, and to meet the requirements of the regulatory rules. The welded pipe should be able to accept a certain internal pressure, if necessary, carry out a pressure test of 2.5Mpa, and insist on no leakage for one minute. Answer the application of eddy current testing to replace the water pressure experiment.
Eddy current testing is carried out in accordance with GBT7735-2004 "Inspection Methods for Eddy Tube Eddy Current Testing". The oil-immersed transformer said that the eddy current flaw detection method is to fix the probe on the frame, and the flaw detection and the weld seam are kept at intervals of 3~5mm. All the welds are scanned by the rapid movement of the welded pipe, and the flaw detection signal is passed through the eddy current flaw detector. Proactive disposal and active sorting, the intention to reach the flaw detection. After the flaw detection, the welded pipe is cut with a flying saw according to the regular length, and the inverted frame is taken off the line. Both ends of the welded pipe should be chamfered at the flat end, the symbol is printed, and the product tube is wrapped in a hexagonal package and then shipped.
Although the straight seam welded pipe is widely used because of its various characteristics, we still need to pay attention to its quality problems in order to eliminate the safety hazard.
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