• The HBC manual operator has an alloy steel worm shaft and a bronze worm gear. Buried and submersible operators are equipped with non-corrosive input shafts.
  • On all operators, except for buried service, a valve position pointer is provided as a standard feature. Handwheels are optional and can be furnished in various sizes.
  • All operator sizes can be supplied with factory-mounted Limitorque electric valve actuators or can be readily converted to motor operation in the field using Limitorque electric actuators.
  • The speed of operation for butterfly, plug, or ball valves when motor-operated can be varied over a broad range, limited only by motor speed and available gear ratios.
  • All HBCs are built to meet AWWA requirements. AWWA input limit stops are available for non-motorized applications.


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The Limitorque HBC series worm gear operators excel in diverse applications. Their dependability has been proven in the most demanding situations, ranging from nuclear power plants, to large damper operations, to power plant flue gas desulphurization. Equipped with a handwheel, the HBC can be used to manually operate butterfly, plug, and ball valves. Combined with a Limitorque electric actuator (such as the SMB, L120, or MX), the Limitoque HBC provides powerful and responsive motorized operation. These combination actuators provide a wide range of output speeds and output torques to 93,000 ft-lb (126,100 N m). HBC operators feature an optional 360° worm gear for use in guillotine damper and radial gate applications. Whether manual or motorized, depend on the HBC for easy valve control — even in tough installations


  • Nuclear and fossil fuel power generation – The HBC has been successfully tested in conjunction with the SMB electric actuator to IEEE standards for environmental and seismic conditions for nuclear plant service. Whether inside containment in safety-related applications or installed on flue gas desulphurization systems or large diameter butterfly valves in fossil fuel power plants, the rugged and reliable HBC delivers outstanding performance year in and year out.
  • Petroleum refining and transmission – HBCs are at work in these quarter-turn valve applications, providing consistent, worry-free operation. In the plant or on pipelines in any climate, the HBC is suited to a broad range of service conditions and temperatures from extreme cold to the desert heat.
  • Water and wastewater treatment – HBC worm gear operators are found in these applications where specifications demand a product with a long history of dependable operation under severe and critical service conditions. The demonstrated excellence in design and functionality make the HBC the operator of choice when nothing less than proven reliability is required.

The Limitorque HBC provides key advantages for quarter-turn actuation

  • Enables manual operation
  • Adapts multi-turn actuators to quarter-turn applications
  • Covers a wide variety of output speeds and torques

Spur gear attachments increase your options

The Limitorque HBC can be equipped with an optional spur gear attachment to further reduce input torque requirements— making it possible to operate even high-torque valves with a handwheel. Motorized applications can also incorporate spur gear attachments to reduce input torque requirements, allowing the use of smaller, less costly actuators to operate the valves.

To achieve specific operating/stroke times, please inquire about alternate spur gear ratios that are available for many larger valve applications.

Expand control capabilities with motorized operation

The Limitorque HBC can easily handle valve positioning and modulating tasks when matched with a Limitorque electric actuator such as the L120, SMB or MX. The HBC is used not only in quarter-turn applications, but can be provided with a 360° output for use with manually operated and motorized multi-turn devices such as guillotine dampers and radial gates.



  • Acid Transfer
  • Aerospace
  • Agriculture
  • Alkylation
  • Auxiliary
  • Boiler Circulation Systems
  • Boiler Circulation Systems
  • Boiler Feed
  • Boiler Feedwater Systems
  • Boiler Feedwater Systems
  • Boiling Water Reactors Non-safety
  • Catalytic Cracking
  • Caustic and Chlor-Alkali
  • Condensate Systems
  • Condensate Systems
  • Construction
  • Cooling Systems
  • Cooling Systems
  • Cooling Water – Metals
  • Crude Handling and Treatment
  • Crude Pipeline
  • Delayed Coking
  • Desalination
  • Descaling
  • Dewatering & Water Supply
  • Digester
  • Distillation
  • Heavy Oil and Upgrading
  • Hydrocraking
  • Hydrotreating
  • Leaching Acid,Logistics and Tank Farm
  • Miscellaneous Services
  • Miscellaneous Services
  • Nuclear Power
  • OEM
  • Plating
  • Pressurized Water Reactors – Non-safety
  • Primary Processing
  • Products Pipeline
  • Scale Recycle
  • Slurry Processing
  • Slurry Transfer
  • Solvents
  • Steam Systems
  • Steam Systems
  • Utilities
  • Waste Processing
  • Wastewater Collection and Treatment
  • Water Handling and Treatment
  • Water Injection
  • Water Supply and Distribution


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