Power tong
A power tong for use during installation and dismantling of pipes when drilling in the ground, such as is known from e.g. petroleum production, comprising a drive ring and at least one clamping device, where the clamping device is arranged to grip a pipe string, the power tong being equipped with a driving mechanism for rotation of the clamping device about the longitudinal axis of the pipe string, and where the clamping device communicates with a fluid supply via a swivel ring that encircles the drive ring.
1. A power tong for use during installation and dismantling of pipes when drilling in the ground, said power tong comprising a drive ring and at least one clamping device where the clamping device is arranged to grip a pipe string, the power tong being equipped with a driving mechanism for rotation of the clamping device about a longitudinal axis of the pipe string, and where the clamping device communicates with a fluid supply via a swivel ring that encircles the drive ring, and a plurality of the clamping devices are gathered in a group, where the group of clamping devices are removable from the drive ring;
the clamping device having at least one piston in a cylinder, the piston communicating with the fluid supply via the swivel ring that encircles the drive ring,
the cylinder and the piston are double acting, wherein a plus side of the piston is in communication with a first passage in the swivel ring; and a minus side of the piston is in communication with a second passage in the swivel ring.
2. A power tong in accordance with claim 1 , the clamp device further comprising a removable gripper.
3. A power tong in accordance with claim 1 further comprising a back-up tong.
4. A power tong in accordance with claim 3 , further comprising the power tong together with the back-up tong being vertically displaceable along at least two guide columns.
5. A power tong in accordance with claim 4 , further comprising the guide columns are disposed on diametrically opposite sides of the pipe string.
6. A power tong in accordance with claim 4 , further comprising the power tong and the back-up tong being independently displaceable vertically.
7. A power tong in accordance with claim 3 , further comprising a space between the power tong and the back-up tong shielded by a collecting bellows, the collecting bellows being positioned so as to collect a content of the pipe.
8. A power tong in accordance with claim 3 , further comprising the power tong and the back-up tong being displaceable vertically on a chassis.
9. A power tong in accordance with claim 3 , further comprising the power tong and the back-up tong being horizontally displaceable along a chassis.
10. A power tong in accordance with claim 1 , further comprising the drive ring being in connection to more than one motor.
11. A power tong in accordance with claim 1 , further comprising at least one weight compensation cylinder between the power tong and the back-up tong.
12. A power tong in accordance with claim 1 , the backup tong further comprising a lifting device.
13. A power tong in accordance with claim 1 , further comprising pipe thread cleaning and lubrication equipment.
14. A power tong in accordance with claim 1 , wherein said group of clamping devices comprising a plurality of clamps.
15. A power tong in accordance with claim 1 , each of the clamps comprising a hydraulic cylinder and a hydraulic piston operable to open and close the clamp.
16. A power tong in accordance with claim 15 , further comprising the hydraulic cylinder and piston being removable from the drive wheel with the drive wheel installed in the power tong.
17. A power tong in accordance with claim 1 , further comprising the drive ring being undivided.