Tooling, hardware, and pump kits for accurate, repeatable bolt loading. Trusted by turbomachinery OEMs and end users worldwide for steam turbines, gas turbines, compressors, and pipe flanges.
Bolt tensioning is a method of tightening and loosening bolted connections using hydraulic power. A high-pressure hydraulic pump is connected to the bolt tensioning tool using a semi-flexible hose. The tensioner generates a large axial force proportional to the input pressure which stretches the stud, the nut is tightened down against the flange, and the hydraulic pressure is released. The bolt and nut now retain the desired clamping load.
Preload scatter as low as ±5%, compared to torque methods that can yield variances up to ±30%.
Tensioning applies a purely axial force, eliminating the thread friction that causes galling in high-load fasteners.
Purely axial force stretches the bolt. Since the nut is turned down independently, frictional resistance is significantly reduced.
Multiple tensioners can be linked together and powered by a single pump kit, reducing installation times significantly.
Watch a live demonstration of Riverhawk's hydraulic bolt tensioning process.
Our engineering team designs standard and fully custom tensioners for any application. Contact us with your stud size, pressure requirements, and application details.