HYDRAULIC BOLT TORQUING
This tightening service provides a simple and safe method for ensuring controlled tightening and loosening of bolts. A wide range of light, compact, safe and easy-to-use hydraulic torque tools are available; and VED’s wrenches are able to accommodate a torque load of 80,000 ft-lbs. (108,465Nm)
Repairs that are performed on your plant’s equipment, valves or pipes are only as good as the bolts that hold themall together. That’s why it makes sense to partner with a company that utilizes the highest-standard bolting techniques and technologies. VED provides complete, high-quality Bolting services – from design to final tightening and measurement on a range of 3/4” up to 4” or M20 to M100. Our bolted connections are engineered to be the most accurate mechanically-fastened connections in the industry, in order to support loads up to 2600kN.
VED’s Bolt Tensioning service is an accurate method of tightening threaded fasteners and subsequently inducing load through advanced hydraulic technology – all without directly turning the nut thereby avoiding frictional losses. Bolt Tensioning insures that gaskets are compressed as required by the manufacturer in order to achieve optimum joint integrity.
MONITORING OF RESIDUAL STRESS VALUES WITH ULTRASOUNDWAVES
The monitoring of residual stress values, combined with tightening with dynamometric key, or, especially, controlled bolt tensioning, is used for checking the correspondence of the residual stress value to the theoretical value required. The bolt measurement technique utilises ultrasonic method, which measures the length of time it takes for an ultrasound pulse to travel from one end of the bolt to the other; this measurement made both before and after the controlled bolt tensioning, reveals the elongation of the bolt and then the stress applied on it. The ultrasound wave comes from a transducer placed to one end of the bolt; for a right measurement, this system utilises a sensor to consider the deformation by temperature. This measurement is then registered on a magnetic medium and filed, therefore it allows to knowthe history of the bolt and it offers an effective support in terms of safety.