Advanced hydraulic bolt tensioning tools
02 September 2019 | Web Article Number: ME201915811
BMG’s Nord-Lock bolting solutions now include Boltight hydraulic bolt tensioning tools, 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,” said Maryna Werner, business unit manager, BMG’s Fasteners division.
“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, due to friction.
“Boltight hydraulic bolt tensioners - manufactured to stringent global quality and safety specifications - use high-pressure hydraulics and a pre-determined 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.”
Werner said BMG specialists work closely with customers in numerous industries to meet challenging bolting requirements. The company offers a wide range of standard and customised bolt tensioning tools to optimise bolt tightening during the construction of new plants and equipment, or for maintenance operations.
“Boltight tools provide continuous performance, without the need for frequent maintenance and repair. Added to this, the fast and efficient turnaround and reliability of these tensioners is vital to saving time on site and for the controlling of running costs.”
The Boltight operating principle is based on the flow of hydraulic oil into the load cell. The load generated by the load cell is transferred into the puller and the puller then transfers the load directly into the bolt. The nut lifts clear of the flange surface due to bolt stretch and the socket is used to turn the nut down, retaining the load.
The equipment is 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.
In the wind sector, the Boltight range provides reliable tensioning solutions for critical joints on offshore and onshore wind turbines, as well as associated structures.
Boltight tools are also used extensively throughout the oil and gas industry, where reliable and accurate bolt tightening is critical to operational efficiency. Standard bolt tensioners are used on onshore and offshore pipeline flanges, compact flanges, heat exchangers, cranes, pumps, valves and for other critical bolting applications. Xtra load bolt tensioners are recommended for higher loads and for restricted space applications.