Vallourec

Herve Salkin

Didier Grare

Bernard A Plaquin

Louis Fradin

A device for determining when a threaded joint for steel tubes having a male element (1) with external threads (3) with a screw limiting stop (5), and a female element (2) with corresponding internal threads (4) and a corresponding screw limiting stop (6) is properly made up is provided. The device comprises a strain gauge (12) and means (10, 11) for applying said gauge on the external surface of the female element (2) such that the gauge can measure superficial deformations of the female element (2) in the longitudinal direction along one of the generatrix of the female element.

Device for determining when a threaded tube joint with screw limiting

A process is provided for executing the screwing of a threaded joint for steel tubes, designed especially for the petroleum industry, of the type having a male element (1) with external threading (3) and female element (2) with internal threading (4), as well as at least one pair of screwing limit stops (5, 6). A strain gauge which allows the instantaneous determination of longitudinal deformations of the external surface along a line of the female element (2) is applied to the external surface of the female element (2) at a certain distance from the plane of the screwing limit stop and on the side of said plane which is opposite to the threads (3, 4), and the screwing down of the joint is executed until the indications provided by the strain gauge corresponds to an extension of a predetermined value of the surface of the female element (2) along said line at the level of the gauge.

Process and device for executing the screwing of a threaded joint for

The invention provides a process for the determination of the make-up torque to be applied on a joint for pipe, destined to the petroleum industry according to which a reference mark is set on the male element and on the female element, so that when the two reference marks are brought to face each other, the make-up restriction stops (2) on the male element (1) and on the female element come into contact with each other; that after having applied a grease, we proceed to make-up by applying sufficient torque to cause one element to rotate with respect to the other one, at a predetermined angle beyond the point where the reference marks are facing each other, and we proceed to measure the torque; that this operation is repeated on a sufficient number of joints; and that a determination is made of the range of torques to be applied on the joints of this type with the grease that has been used.

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Aulnoy, France

Herve Salkin