CLAMPING WELL CASINGS

摘要

A clamp for clamping two concentric tubes (50 and 52). The clamp has axially moveable tapered components (72 and 74) that can be pulled over one another in an axial direction to provide a contraction of the internal diameter that grips the smaller diameter tube (52). In one embodiment, a spacer is fitted to allow the tapered components (72 and 74) to be held apart until the tubes (50 and 52) have been correctly positioned. The spacer is then removed, and the tapered components (72 and 74) are drawn together to effect the clamping. A hydraulic ram can be provided to separate the tapered components (72 and 74) should readjustment be required. In another embodiment, the larger diameter tube (50) is made with a relatively thin wall, so that it can be distored inwards to grip the smaller tube.