Accelerate your turbine outage with the Hydraulic Casing Closure System using Hydraulic Nut Technology. Quickly close and open inner and outer shells in about 2 to 4 hours.

Bolttech Mannings’ system eliminates the need for bolt heating and torque between initial breakout and final closure by pressurizing select studs simultaneously, which quickly generates loads sufficient to simulate operating conditions. Initial installation and final removal of the system can be completed in 2 to 4 hours.

How It Works

Specially designed Hydraulic Nuts are used to maintain loads on the inner shell while the outer shell is installed for alignment checks or other maintenance procedures. Since each Hydraulic Nut is configured to stud size and threads per inch, the system components can be utilized on the inner and outer shells of the HP, IP and LP as well as control valves on other bolting flanges.

The Hydraulic Turbine Casing Closure System can also be used to speed up final closure. Each system can be configured to your particular outage requirements. The system is designed to accommodate virtually every manufacturer turbine model. It can also be configured to simultaneously pressurize the HP, IP, and LP sections, if required for speed. The Hydraulic Turbine Casing Closure System is now available in all size ranges from 2-inch to 6-inch nuts.


The operation of the Hydraulic Turbine Casing Closure System is fast and easy.

The operator tightens the Hydraulic Nuts on the stud. The operator then connects the hoses, which have quick-connect fittings, from the pump to the Hydraulic Nut. After running the pump to achieve a pre-determined pressure, the operator tightens the Locking Collar and releases the pressure. The Locking Collar retains the load in the stud. The Hydraulic Turbine Casing Closure System is specially designed for checking turbine internal clearances. These compact Hydraulic Nuts temporarily replace existing nuts on the inner and outer casings during the “tops-on, tops-off” process. When pressurized, they provide the clamping force to overcome casing distortion.

Benefits Gained

  • Portable, safe, and easy to use
  • Tremendous Time Savings
  • Reduced man-hours
  • Shortens Critical Path Schedule
  • Eliminates dangerous CAL-RODs and gas heating

Hydraulic Turbine Closure Media