The relatively shallow pattern (44) is designed to hydrostatically prevent a friction lock of the sealing faces when the shaft is at or near to a stationary condition.

The inner sleeve is arranged to be radially deformed, thereby producing a surface pressure on the shaft, for friction locking of the shaft (10) relative to the hub (11).

Because the temperature in the double pipe may change it has been found necessary to insert in long pipes expensive axial compensators such as U-bent pipe elements.

Measuring means (9) integrated with the outer sleeve (3) is arranged to measure the strain of the outer sleeve (3), which strain is an indication of said friction locking.

The clip, in various forms, is arranged to frictionally lock between the hem of the horizontal leg of the wall angle and the vertical leg.

A reverse bend (16b) having yieldable portions (16f, 16f') in opposition to one another on each side of this bend (16b) to serve as a receptacle for frictionally gripping a conductor, a pin (7) which can be inserted through an opening (16e).