METHOD FOR PREPARING PIPELINE PIPES BUTT-ENDS FOR WELDING AND CENTERING SKID FOR PREPARING PIPELINE PIPES BUTT-ENDS FOR WELDING Russian patent published in 2010 - IPC B23K37/53 

FIELD: mechanics.

SUBSTANCE: invention may be used for mechanical levelling of pipe butt-ends, in particular - with large diametre pipes, when centering the welded joint prior to welding during construction and repair of pipelines and pipe assemblies. Selected for welding are pipes with butt-ends whose oval perimeters difference does not exceed the allowance specified. Mechanical treatment proceeds in the radial direction; subject to the treatment is the wall of at least a single pipe all along its perimetre at minimum five spots till the geometrical parametres match the similar parametres of a reference butt-end providing for metal residual plastic deformation. The treatment on the inside and the outside of the pipe wall proceeds simultaneously. The centering skid used for the method implementation has working tools with power drives on the inside and the outside of the pipe wall mounted on a circular-shaped frame and tools for definition of the pipe parametres and deformation control.

EFFECT: invention provides for production of standardised weld clearances during pipe matching due to maintenance of the oval perimetre during correction and the minimum differences of radius vectors of the reference oval and that being mated.

4 cl, 3 dwg