HRT Hydraulic Tensioning System

The Riverhawk HRT Hydraulic Tensioning System is suitable for high temperatures applications and is retrofitable to existing installation requirements. High load capacity is achieved by virtue of placing the hydraulic cylinder above the stud and nut maximizing the hydraulic working area.

The Riverhawk HRT Tensioning System is an enhancement of Riverhawk’s line of standard hydraulic nuts and tensioners which already offer the industry versatility, flexibility and modular design. With Riverhawk’s hydraulic tensioning system, design limiting considerations, such as coefficient of friction due to torquing, are no longer a concern. This high temperature tensioner for studs and nuts eliminates the need for temperature limiting seals, lubricants, and coatings.

In operation, hydraulic pressure is introduced via a port in the cylinder. The reactive force thus generated is transmitted through the cylinder and, in turn, through the nut to pull on the stud. In this hydraulic tensioning system, a circle of axial ports pass through the nut. Contained within these ports is a series of rods which transmit force from the bottom of the piston through a common washer to the flange face. When the stud is tensioned to a predetermined shank stress, a retaining ring threaded on the outside diameter of the nut is spun down into contact with the flange. The retaining ring serves to maintain the separating force between the nut and flange. The load cell portion of the system including the tensioner piston, tensioner cylinder and rods is removed after tensioning is complete. This eliminates temperature limitations that seal materials and oil would impose if they were to remain in the assembly during service as is the case in other hydraulic nut configurations.