SCT – Self Contained Tensioner

The remarkable SCT - Self Contained Tensioner (formerly known as The Biach SCT) brings greater safety, reduces manpower and shortens downtime to a critical task. Quick connect/disconnect design for fast RPV performance based on decades of field proven use with our QD and QD-H tensioners.

Power needed: 460-480VAC at 10 amps High Speed Industrial Network Communication Protocol Communications via Cat 5 Ethernet Cable bundled with power distribution cable

Pressurisation time: less than 20-30 seconds (based on 1 or 2 stage design)

Accuracy: +/- 15 psi at 10,000 psi maximum pressure

Weight: 3600 to 4600 lbs. (depending on single or two stage cylinders)

Height: comparable to existing QD or QD-H style stud tensioners

Stud Engagement Interface:
Quick Connect / Disconnect design for fast performance based on over 30 years of field proven use. Can engage annular groove design or helical thread form RPV studs.

Safety Features:

  • Electronic Limit Switches for:
    • Verifying full latch on pull system engagement to RPV stud
    • Checking piston overstroke travel to protect equipment components
    • Monitoring piston return status to prevent loss of stroke at next step
  • Secondary Seals to route fluid by pass to reservoir and prevent external leakage
  • Text Style Instructions via an LCD screen to coordinate sequence and integrate operation
  • High Pressure Safety Valve to cease high pressure operation as a secondary system to electronic overstroke limit switch in preventing piston overstroke.
  • Emergency Stop button on each control panel to cease all operation

Integrated, Built on Pumping System:

  • Saves valuable refuel floor space
  • Eliminates rigging of and potential leakage from interconnecting hoses (currently used)
  • Reduces storage requirements

Performance Enhancements:

  • Built in Elongation Monitoring System (EMS) provides instant elongation reading feedback which allows immediate re-tensioning if reading is out-of-spec and eliminates need to perform trim adjusting passes upon completion.
  • Complete hydraulic operation: latching of pull system, pressurisation and piston return. Does not require any air supply or create any air born contamination through air exhaust systems.
  • Ram Actuators for piston return process eliminates potential of hydraulic leakage at tensioner top plate during piston return phase due to flange rotation conditions.
  • System set up for one master driver though at any time another unit may become the driver.

Design Integrity:

  • Life of Plant for major components
  • High strength steel (vs. casting) housing component which faces repeated compression stresses
  • Modular design for quick change out or for future technology replacement or upgrade
  • Allen Bradley PLC controls for industry wide acceptance and reliability

Low Maintenance Costs:

  • 10 year spring energised hydraulic seals reduce periodic overhaul, RWP, crew and support costs
  • Elimination of current central pump (EPN) service, and periodic replacement of hoses and cables

Reduced Crew Requirements (one man per tensioner):

  • Fatigue eliminated through turn-of-the-switch stud engagement
  • Simple movement left or right and hoist operation up or down through built on controls
  • Integrated communication system coordinates operation

SCT – Self Contained Tensioner

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