Hydraulic bolt tensioning is a semi-automated process, substantially faster than bolt torquing, and delivering a precise residual bolt load. Bolt tensioning enables a hydraulic load, more commonly known as the applied load, to act upon the stud bolt. The effect is similar to the stretching of a spring, and the stud bolt elongates. This extension is retained by simply tightening the nut. Given the hydraulic load was calculated to cause the stud bolt to retain a specified residual load when the tensioner is released, there is an inherent high degree of accuracy and repeatability not available with bolt torquing. The most accurate residual bolt loading and uniform compression of a joint gasket, is achieved by multi-stud tensioning. In a gasketed flange, no less than 50% of the bolts should be tensioned simultaneously, with 100% tensioning providing the greatest accuracy and shortest assembly times.