Bolt stretcher is generally composed of hydraulic pump, high pressure hose, pressure gauge and stretcher. The hydraulic pump is the power source, the pressure gauge reflects the output pressure of the pump, and the high-pressure hose connects the hydraulic pump and the stretching body. The drawing body is the executive component to realize the bolt stretching. It is mainly composed of piston cylinder, piston, supporting bridge and tension nut.
When working, the high-pressure oil output by the power source is sent to the piston cylinder 3 through the high-pressure hose. Under the pressure, the piston in the piston cylinder moves up and drives the pull nut to move up. The stretching nut is connected with the working bolt thread, so as to lengthen the working bolt, so that the bolt elongation reaches the required deformation, and the deformation is controlled within the elastic deformation range. Then the pre tightening or disassembly operation is carried out, and finally the working bolt is restored to its original shape by hydraulic or mechanical return to complete the operation.