The change of electric submersible pump: the rotation of the pipe thread will be replaced by L-D, it can make the electrical submersible pump in the startup and normal running torque will not cause screw loosening. Of course, in the process of electric submersible pump, due to overload, underload and other causes of electrical power, will produce torque down at the moment, but this torque is much smaller compared with the starting torque, does not cause the electric submersible pump upside down; in addition, to strengthen the existing anti down measures, strictly control the process of anti welding down the block, to ensure the welding quality, can also play a role to prevent undercut.
The above measures to prevent the reverse button, can not solve the problem of reverse deduction. Because the torque caused by the reverse button is not eliminated, of course, it is not possible to completely eliminate the reverse torque. But some measures can be taken to control the torque in a certain range. For example, electric submersible pump in the top section of the junction with the tubing, the movable joint, can make down torque control in a certain range, to avoid the occurrence of upside down. The working principle of the joint, the assembly, by adjusting the screw, the proper control of the pressing force between the steel ball and the joints, thus ensuring the electric submersible pump in normal operation, the upper ring and the lower ring does not occur between the relative rotation. When the torque exceeds a certain value, the upper joint will be steel ball
