Hydraulic bolt tightening methods enhance accuracy

Engineering components supplier BMG’s Nord-Lock bolting solutions now include Boltight hydraulic bolt tensioners, which are used to tighten bolts simultaneously, ensuring even preload in industrial applications and extreme environments, where bolt load accuracy is critical.

Advanced bolting technology in large machines and equipment eliminates the risk of loose or over-tightened bolts and is critical to ensuring optimum performance and safety on industrial sites. As bolts increase in size, so the load critically increases and operators are faced with the challenge of achieving the correct bolt elongation, to ensure bolt load accuracy.

When tightening a bolt using traditional torque methods, it can be difficult and sometimes impossible, for the operator to achieve the correct bolt elongation, owing to friction.

Boltight tensioners – manufactured to stringent global quality and safety specifications – use high-pressure hydraulics and a predetermined pressure to make on-site bolting jobs safer, faster and more efficient. These tools have been specially developed to axially stretch the bolt. The nut is then rotated down the joint face, accurately locking in the bolt load.

The Boltight tensioner operating principle is based on the flow of hydraulic oil into the loadcell. The load generated by the loadcell is transferred into the puller and the puller then transfers the load directly into the bolt. The nut lifts clear of the flange surface owing to bolt stretch and the socket is used to turn the nut down, retaining the load.

Boltight tensioners are suitable for use in all industries where critical bolting requires accurate and reliable tightening. In power generation, these tools are used for bolts on pipes, pumps, valves and engines.