Hydraulic Tensioning Information
When you hold a stud or a bolt, it is hard to imagine that this sturdy object can act as a spring. In fact, the fasteners in a bolted joint do just that. They must be stretched at assembly with enough force to keep the joint firmly clamped together when it is placed in service. The joint can fail if the load in the fasteners is too low, too high, or if it is not uniform in every fastener.
Hydraulic tensioning systems are the simple and efficient answer to this problem. It is the tightening method that will help you control the high costs of incorrectly tightened joints by reducing leakage and extending maintenance intervals.
HTI's hydraulic tensioning systems are a more accurate and efficient tightening method than traditional tightening systems.
Advantages of Hydraulic Tensioning
Accurate and Repeatable Stud Loading
A tensioner is merely a special purpose hydraulic cylinder. The load it applies to a stud is a direct function of the cylinder’s area and the hydraulic pressure supplied by the pump. Since we closely control these functions, the load applied to the stud is highly accurate. When tightening studs with torque, the friction between the stud, nut, washer and flange face plays a large, and often unpredictable role in the stud’s final tension. These unknowns are eliminated with tensioners.
Uniform Stud Loading
Even loading in each stud is important, especially on applications with gaskets that must meet fugitive emission and strict environmental regulations. HTI recommends multiple tensioners for applications with more than one stud. These tensioners are coupled to each other and to the pump. As the hydraulic pressure increases, the load in every stud is the same, and the flange comes together simultaneously and evenly.
Time and Labor Saving
Multiple tensioners, working together, save time. One operator can work most applications with a minimum of effort.
Ease of Use and Safety
Tensioners have a high power to weight ratio. They are lighter, less bulky and much easier to use than torquing tools. Tensioners are quiet and are safer to use than slugging wrenches or bolt heaters. The air or hand-powered hydraulic power supplies are inherently explosion proof.
Increased Stud Life
There is no thread seizing or galling with tensioning. This leads to greatly increased stud life.