Centering coupling


Centering coupling influence (further CC) to the technological process of anticorrosive insulation coating.

Pipes coated inside by anticorrosive insulation have uncolored areas at edges. Uncolored area covers pipe circle and has width from 30 till 50 mm from pipe end. It is necessary for welding works during pipelines assembly. Pipe is coated from external side after it coating from inner side. Process of external anticorrosive coating requires continuous pipes arrival to an extruder. In order to provide continuous pipe arrival it is necessary to eliminate the gap between moving in a flow pipe ends. Pipes have axial curvature and transport line adjustment originally makes it impossible to synchronize angular rotational velocities of coating pipes. It leads to pipe ends impact. Jam of end chamfer occurs because of pipe ends impact and it is inadmissible according to regulations. This way of anticorrosive insulation coating leads to coating of pipes chamfer. It adversely affects the duration of welding during pipe fitting. This technology leads to air binding under insulation layer in connection with moving of pipe ends relative each other. If a pipe has this defect it rejects as defective.

The source of its defects is axial shift of pipe ends. There is a special method for elimination of this technological problem:

Pipe ends are coiled from external side by preventive tape which can easily be removed. Then centering coupling is set in the internal side of pipe end and is fixed by special equipment. In the reverse side of its coupling rollers are set for pipe catching and centering of joints of two consecutive in a line pipes.

VKS-Techno centering coupling has weight 100 kg (Ф1420 мм.). Centering coupling has not only centering elements of pipe ends and it also has end props which are used for pipe ends protection from mechanical defects. Centering coupling is designed specifically. It doesn’t need to be changed to other wall thicknesses. There are no defects (scratches, dents, risks, point defects, etc.) on a pipe body during disassembling of centering coupling. The rest of grit in a pipe doesn’t lead to scratches inside pipe in the end area. It reaches because of special rollers construction. Hard construction of centering coupling allows to produce strong and reliable end pipe centering during the whole technological cycle. Centering coupling produced by VKS-Techno has minimum number of elements and low coefficient of aerodynamic coefficient. It makes possible to use it in coating technology with air suction cleaning inside a pipe to remove grit and pour off water.

Size range of our centering couplings:

  • For work with internal pipe coating the diameter from 57 to 2500 is used.
  • For work without internal pipe coating the diameter from 57 to 2500 is used.