On-line testing of welded pipe

Welded pipe at the factory to go through rigorous testing to ensure compliance with the provisions of pipe quality standards and user requirements.
Pipe inspection items generally include: factory inspection items have the appearance quality, straightness, dimensions, and other types of weld quality inspection items (flattening, flaring, bending, etc.). Detection means available weld pipe either way hydrostatic testing, ultrasonic testing, eddy current testing in.

Pipe pressure test procedure:
  1. feed. Quantitative feeder or chain pipe pressure test will be sent by the root hydraulic machine supporting roller frame, the support roller frame into two test tubes and then the position of the head centerline.
  2. clamped. Fixed pressure test before and after the head position, the tube clamped between the front and rear pressure test head, hold the tube clamping device.
  3. filled with water. By a low pressure pump filled with water to the tube, the tube by means of air pressure in the test head of the unloading valve or discharge valve. The inner tube to be filled with water when the drain air, unloading valve or the exhaust valve is closed.
  4. turbocharger. Pressurized tube through the booster allows water to test pressure, pressure test test tube.
  5. packing. After reaching the test pressure specified in accordance with the requirements of the steel pipe packing, maintaining the pressure some time.
  6. to confirm. Unqualified steel pipe symbol processing to distinguish the qualified pipe.
  7. relief. After reaching the dwell time, pressure relief valve automatically opens, the tube pressure drop.
  8. discharge. Mobile test ram, water is discharged from the pipe, the pipe feeding mechanism with a pull hydraulic press.

Hydrostatic test is the most common, most direct and most reliable way of weld line inspection, is in a variety of hydraulic test machine. When the pressure test, the first pass low-pressure water, filled the entire root steel side by side to make the air, and then to test pressure prescribed way through the booster and stabilize the prescribed time, at the test pressure, when no steel welds and around wet, spray, water leakage or permanent deformation, is considered qualified.

Weled steel pipe specification, Standard and identification

Welded steel pipe (steel pipe manufactured with a weld) is a tubular product made out of flat plates, known as skelp, that are formed, bent and prepared for welding.