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Plate infeed
Plate infeed symbol
Welding of run-on and run-off tabs
Welding of run-on and run-off tabs symbol
Edge planing
Edge planing symbol

The edges of the plate are first planed parallel in the shape of a double Y bevel. Perfectly parallel and square edges as well as close width tolerances are essential for the forming operation. In addition, this is where the accuracy of the weld bevel and the quality of the seam are predetermined.

Crimping symbol

Over an area of approximately 200 – 400 mm, both edges of the plate are crimped simultaneously to the desired pipe radius. This operation ensures that the pipe meets even strongest requirements with respect to out-of-roundness, including the region of the longitudinal seam.

Our crimping press in Mülheim an der Ruhr / Germany is able to process plate thicknesses of up to 50 mm.

U-ing symbol
O-ing symbol
Cleaning of the slit pipe
Cleaning of the slit pipe symbol
Tack welding of the slit pipe
Tack welding of the slit pipe symbol

Before submerged-arc welding takes place, the open edges of the slit pipe are tack welded together under shielding gas.

This is done in frames (roller cages) which locate the edges exactly and prevent misalignment. The continuous tack weld also serves to retain the weld pool during subsequent submerged arc welding.

Pipe identification
Pipe identification symbol

For identification each pipe is marked with a pipe production number.

Additionally a line, marking the centre of the pipe, is the reference for late non-destructive testing of the weld seam.

Tack weld inspection
Tack weld inspection symbol
Inside seam welding
Inside seam welding symbol

Inside welding is carried out first, followed by outside welding. The tack weld pass is completely fused. In submerged-arc multi-wire welding, up to five welding wires are arranged one behind the other.

Outside seam welding
Outside seam welding symbol

Consistency of weld quality is determined by various parameters: Welding wire and flux, amperage, voltage, welding speed, wire spacing, wire diameter, the angle of the wires relative to one another and to the weld groove, as well as flux height and width. A welding data monitoring system permits online supervision of the production process.

Internal and external pipe inspection
Internal and external pipe inspection symbol
Initial ultrasonic weld inspection
Initial ultrasonic weld inspection symbol

First, each seam is checked visually, inside and out. Our internal quality checks also include ultrasonic inspection of the entire seam, which can also be augmented by X-ray examination and manual ultrasonic testing.

Initial x-ray inspection, filmless radiography
Initial x-ray inspection symbol

Image processing capabilities coupled with support by automatic image evaluation software significantly improve the reliability of inspection and detection compared with conventional film-based methods. Any ultrasonic indications are checked automatically and with pinpoint accuracy. We are proud to be the only large-diameter pipe manufacturer, that conducts all radiography tests with digital technology.

Mechanical expansion
Mechanical expansion symbol
Sampling and destructive testing
Sampling and destructive testing symbol

In parallel with the nondestructive tests carried out in the large-diameter pipe mills, the mechanical-technological properties of the base metal and the weld are measured in accordance with agreed specifications.

Facing symbol
Hydrostatic testing
Hydrostatic testing symbol

Pipes have to pass yet another demanding test while still in the mill: by means of internal water pressure, they are stressed close to their yield point – in other words, far above the operating pressures they will face in service.

Final ultrasonic weld inspection
Final ultrasonic weld inspection symbol

The UT-device is a modern computer-controlled and fully automated machine with up to 10 probes for longitudinal and 4 probes for transverse testing with the latest water nozzle technology.

Final x-ray inspection, filmless radiography
Final x-ray inspection symbol
Grinding of weld reinforcement at the pipe ends
Grinding of weld reinforcement at the pipe ends symbol
Magnetic particle inspection of pipe surfaces
Magnetic particle inspection of pipe surfaces symbol

If required, internal and external surface inspection of the pipes can also be performed by magnetic particle inspection.

Bevelling of pipe ends
Bevelling of pipe ends symbol

In a final step, both pipe ends are bevelled simultaneously in a single operation to ensure that the finished pipe ends are square and parallel for girth welding in the field.

Automatic measuring of pipe ends
Automatic measuring of pipe ends symbol

The geometry of all pipe ends is fully automatically measured with pipe end measurement equipment based on optical laser sensors.

The laser measuring device checks the inside and / or the outside dimensions of the pipe ends according to the QA / QC instructions for this pipe. Basically the following dimensions are checked and recorded by PRODIS: diameter, roundness, circumference, wall thickness and peaking of all pipe ends.

Customer requirements on QA / QC are linked to the PRODIS system. PRODIS checks the results against the QA / QC requirements. Only pipes whose ends fulfil all requirements of QA / QC instructions will be released.

Magnetic particle and ultrasonic inspection of both pipe ends
Magnetic particle and ultrasonic inspection of both pipe ends symbol

The pipe ends are non-destructively tested for laminations and inclusions by magnetic particle and ultrasonic inspection. Only perfect pipe ends permit defect-free girth welding in the field.

Final inspection of surfaces and pipe geometry
Final inspection of surfaces and pipe geometry symbol

The final inspection includes additional checks of the entire pipe at diameter, wall thickness, bevel edges, roundness, etc. on the pipe body and ends.

Generation of certificates
Generation of certificates symbol

Once all production and inspection steps have been carried out and all specification requirements have been fulfilled, the customer documentation is prepared. All results are listed, and certificates are produced.

This is another job taken care of by EUROPIPE's intelligent Production Control and Information System, PRODIS.