Application

TVG-U wide-range hydraulic internal cutter cuts and retrieves tubing during well interventions. 

Design

The cutter consists of a crossover, that connects the cutter to the motor shaft, a body with inserted knives, a mandrel, a spring, a retainer ring, a centralizer sleeve, a mandrel extension, a centralizer drag spring, a sub, an O-ring and a jet. 
Concurrent rotation of the cutter and pressure surge in the chamber force the mandrel to drive knives outwards from the body slots. The spring and retainer ring enable stepless and uniform feed to the knives.
After cutting is finished, the pressure drops and piston returns to its initial position. Installed at the bottom, the centarlizer diminishes play of the cutter during its operation. The centralizer consists of three drag springs attached with screws. While running-in, the drag springs push against the walls acting as a plain bearing.