Hoesch Werke Aktiengesellschaft

Hoechst Aktiengesellschaft

Hoesch Aktiengesellschaft

Friedrich-Otto Koch

Adolf Peeck

Hans-Jurgen Wahl

Werner Wennemann

Heinz Gross

Rolf Krebs

Peter Schorr

Wilfried Kliesch

Jurgen Duisberg

Hans Spliethoff

Wolfgang Venema

Heinz Strauch, Deceased

Matthias Lang

Robert Scholl

Heinz Grob

Heinz Grosse

A gas-tight joint for pipe linings and risers inside a bore, consisting of a neck with an outside thread and of a matching collar with an inside thread, with a groove in the vicinity of the thread on the collar and/or of the thread on the neck to accommodate a deformable gasket that, when the joint is screwed tight, is demarcated and deformed by the base of the groove in the neck and/or in the collar and by the contour of the thread on the other component. The cross-sectional area demarcated by the base of the groove in the neck and/or collar and by the contour of the thread on the other component once the two components have been screwed together remains constant along the groove and is equal to or larger than the cross-sectional area of the deformable gasket before the components are screwed together.

Gas-tight joint for pipe linings and risers

A method for production of a multi-layer gap-less steel pipe. An inner pipe and an outer pipe are formed from thermomechanically rolled steel strip with high notched bar impact strength by welding. The individual helical welding seam steel pipes of about the same lengths are matched with a difference of less than about one percent between the outer diameter of the inner pipe and the inner diameter of the outer pipe. The matched inner pipe is inserted into the outer pipe and the pipes are mechanically expanded with diameter control to a preset outer diameter of the multi-layer steel pipe. The resulting multi-layer steel pipe has the inner pipe disposed under compression and the outer pipe layer disposed under stress. The presence of a compression stress in the inner pipe provides a means opposed to hydrogen sulfide stress corrosion. The advantages of the helical welding seam steel pipes can be combined such as economic production, advantages relating to crack formation and crack propagation stopping, and the availability of high internal pressure loads upon use of thin, economic steel strip of different yield strength.

Multi-layer helical seam steel pipe

For increasing the resistance of steel pipes or tubes against acidic medium, by a combination of a heat treatment and the use of an alloyed steel, a compressure stress is built up on the side of the tubes or pipes facing the acidic medium, of up to 30% of the yield limit.

Method for making steel tubes or pipes of increased acidic gas resistance

It is necessary to determine the effects of welding pressure in order to control the high-frequency welding process in the manufacture of pipes with longitudinal seams. It has been discovered that measurements of the height of the welding bead provide an approximation that is satisfactory for determining the mass of the bead, which is proportional to welding pressure in known pipe geometry. The height of the bead is transmitted by an optical system to the diode matrix of a commercially available diode-matrix camera. The results are processed to control welding pressure.

Method and device for controlling the welding process in the

A system for non-destructive testing of metallic materials and for, in particular, welding seams. An ultrasonic sensor is employed and ultrasonic defect signals are producted according to the pulse echo method. The ultrasonic defect signals are digitized and the digitized signals are combined with signals corresponding to longitudinal positions along the welding seam. A defect curve is produced form the data resulting from combining the digitized signals with the signals corresponding to longitudinal positions along the welding seam. The resulting defect curve is compared with data from a catalog of classes of defects. The system eliminates the need for manual ultrasonic reinspection of presumed welding defects.

Test system for defect determination in welding seams

Growing community of inventors

Unna-Massen, Germany

Friedrich-Otto Koch