Bolts provide tensile force to hold items in place, and this Tension must be within approximately 80 percent of the bolt’s ultimate tensile strength. The hydraulic bolt tensioner manufacturers produce them to maintain proper mechanical Tension safely. Bolt tensioning involves using mechanical means to stretch the stud bolt physically. The material will stretch when the nut is placed on the bolt. Once the nut is in place, Tension is released when the stud bolt metal returns to its original shape before stretching. This process is called spring tension. When the bolt returns to its original state, it will tighten against the nut to create the appropriate force. A coupling is included to prevent failure during service. A hydraulic bolt tensioner is used to lengthen the stud bolt to achieve the proper preload before the nut is put in place.

How to Use the Hydraulic Bolt Tensioner:

When choosing a hydraulic bolt tensioner, you must analyze various characteristics. Following are the uses of tension adjustment. You should evaluate the bolt diameter, nut size, bolt grade, and washer thickness. Washer diameter Protruding length of free stud and the bolt’s load requirements. You can then check the technical specifications of the hydraulic bolt tensioner to ensure it will provide the proper hydraulic pressure to achieve the desired rate and the required preload.

Procedure for Adjusting Hydraulic Tension:

  • Place the bolt tensioner over the free part of the stud bolt until it contacts the flange.
  • Thread a tensioner puller onto each load cell to connect it to the cylinder piston.
  • Each tensioner is connected to a hydraulic pipe.
  • The tensioner has a locking collar that turns using a tommy bar to push the nut on the joint.
  • Turn the nut down onto the face of the joint until it snaps into place.

When the hydraulic bolt tensioner releases pressure and is removed, the Tension created on the stud bolt is removed like the spring. It returns to its standard shape by shrinking. It clamps onto the joint to make a correct seal. For some types of use, two tensile pressures must be applied. The hydraulic bolt tensioner cannot be installed on each bolt simultaneously. Some bolts are tensioned simultaneously. The hydraulic bolt tensioner is then moved to the remaining bolts.

Types of Hydraulic Bolt Tensioning Systems:

There are two types of bolt tensioning systems. There are systems where all the nuts are tensioned at once; others are tensioned half at once, followed by the other half immediately after. Tightening all the bolts simultaneously will speed up the process but can damage damaged bolts. When you do half and half, a damaged bolt will not cause immediate problems because the other half is still in place. This makes it easier to identify and replace damaged bolts and achieve the most appropriate level of Tension. Both hydraulic bolt tensioner systems work the same way: fit the stud, loosen the nut, and apply Tension to the bolt. When the appropriate level of Tension is reached, the nuts are tightened to the proper torque specifications. This will give you the optimal level of Tension for each bolt and the best mechanical application for your machine.