Normally, in industries, different bolted joints / connections are to be used. These can be easily tightened and untightened as and when required. In medium& heavy industries /plants, different bolted joints / connections are used which require high clamp force. So bolts /studs with bigger diameter are to be used. These bolts / studs require more efforts in tightening & untightening.
Standard hex nuts used in such connections are tightened by the known tightening systems, such as : Ordinary hand or Torque wrench / Hydraulic or Pneumatic impact wrench or Thermal tightening or Sledge hammering methods. These systems do not allow easily to tightening bolts of large diameter, to the stress level required for maintaining safe operations. The force exerted by such method, is insufficient to tighten bolts or studs above M24 effectively, to the required force -tension to maintain continue operational condition. However, when such connections, comes to untightening, such as in maintenance, often creates problems and they can not be dismantled by the way they have been tightened with, and, the only solution is to torch cut, when corrosion distorted threads makes it impossible to unload the bolts.
In Tensioner Nut & Bolt, total clamping force is divided into no. of clamping screw. By tightening the clamping screws, a strong clamp force is generated. This clamping force is directed against a thrust washer and bolt having small friction diameter so it will help to create high clamping force with relatively little torque input.
The clamp forces are transferred through the nut body which is positioned on the main threaded bolt or stud.
A thrust washer is hardened so it is able to transfer the force while protecting the flange face.
The clamp force of many clamping screws and the opposite reaction force of the main bolt head create a strong clamping force on the flange.
The clamp force from the clamping screws creates an equally strong reaction force in the main bolt.