Welded steel pipes shall be subjected to mechanical performance tests, flattening tests and flare tests, and shall meet the requirements specified in the standard. The steel pipe should be able to withstand a certain internal pressure, and if necessary, carry out a pressure test of 2.5Mpa to maintain no leakage for one minute. It is allowed to replace the hydrostatic test by means of eddy current testing. Eddy current testing is carried out according to GB7735 "Steel Flow Test Method for Steel Tubes". The eddy current testing method is to fix the probe on the frame, and the flaw detection and the weld seam are kept at a distance of 3~5mm. The weld is fully scanned by the rapid movement of the steel pipe, and the flaw detection signal is automatically processed and automatically sorted by the eddy current flaw detector. To achieve the purpose of testing.
The welded pipe after the flaw detection is cut with a flying saw according to the specified length, and is turned off the frame by the flip frame. Both ends of the steel pipe should be chamfered with flat heads, printed with marks, and the finished pipe is packaged with hexagonal packaging and shipped.
The main processing methods for straight seam steel pipes are:
Forged steel: A pressure processing method that uses the reciprocating impact of a forging hammer or the pressure of a press to change the billet to the shape and size we need.
Extrusion: It is a steel processing method in which a metal is placed in a sealed extrusion, and pressure is applied at one end to extrude the metal from a prescribed die hole to obtain a finished product having the same shape and size, which is mostly used for producing non-ferrous metal steel. .
Rolling: A press working method in which a steel metal billet is passed through a gap (various shapes) of a pair of rotating rolls, and the material cross section is reduced by the compression of the rolls, and the length is increased.
Pulling steel: It is a processing method in which the rolled metal blank (type, tube, product, etc.) is pulled through the die hole to reduce the length of the section.
For cold processing.
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