Gimpel Steam Turbine Control Valve Cover Torquing

• Eliminate Thread Galling
• Improved Gasket Seating
• Reduced Turnaround Time

Problem:

Traditional torquing methods of valve cover assembly created a non-uniform load distribution resulting in improper gasket seating. Also routine servicing proved time consuming and risk the chance of galling the valve cover studs.

Solution:

Original hydraulic torque wrenching tooling replaced with Riverhawk custom designed external tensioners. Operating in tandem, the tensioners hydraulically stretch Riverhawk supplied, 17" long studs, to achieve a residual 30,000 psi stud stress after relaxation. The 3" diameter studs incorporate an internal tapered thread that mates directly to the tapered tensioner puller screw for stud elongation. The four leg tensioner bridge allows installation in a tightly nested hex cap nut pattern. An accurate preload is achieved quickly with uniform pressure distribution for proper gasket seating.