Limitorque traces its origins back to 1929 when it pioneered the concept of torque limiting in valve actuation. That design quickly became the foundation of its identity—a feature that protected valves from damage under excessive torque. Over time, Limitorque evolved into a trusted brand, and through a series of mergers - it gained global prominence under the Flowserve umbrella.
Limitorque didn't just coast on legacy; it kept innovating. In 1997, the company introduced the MX electric actuator, widely recognized as the world's first "smart" actuator, featuring digital controls, diagnostics, and absolute encoders—without the need for a battery. Since then, Limitorque has introduced advanced lines, including the L120 series, quarter-turn QX models, and rugged SMB versions—each tailored to specific industrial needs.
Reputation & Brand Strength
Limitorque actuators earn respect for their bulletproof reliability and tough engineering. Safety-conscious design is evident, as demonstrated by the widespread use of torque-limiting mechanisms, absolute encoders, and designs that safeguard both valves and operators. Reports highlight over a million installed units, with many still in service after 50 years.
These actuators excel in mission-critical settings, ranging from nuclear power and oil and gas to water utilities and pulp and paper. The SMB line supports nuclear powerhouses and even U.S. Navy systems, while L120s regularly dominate conventional and renewable power plants.
Field testers praise their modularity, durability under extreme temperature swings, and network-ready controls like Modbus, Foundation Fieldbus, DeviceNet, and HART. Professionals trust Limitorque for dependable operation and industry compliance.
Primary Markets & Sectors
Limitorque actuators serve a wide array of industries:
- Oil & Gas: Both upstream and midstream operations use these units for drilling, refining, transport, and terminal duties. Their reliability in hazardous zones stands out.
- Power Generation: From thermal to nuclear and hydro, Limitorque actuators manage feedwater, steam, and shutoff valves. SMB models even meet nuclear IEEE standards.
- Water & Wastewater: Treatment plants count on these actuators for flow control in potable water, sewage, and desalination apps.
- Chemical & Petrochemical: Actuators here help regulate aggressive chemicals, slurries, and corrosive fluids—requiring precision and ruggedness.
- Mining & Pulp & Paper: Heavy-duty electrohydraulic LPS types handle bulk-phase valves and high-torque pipelines.
Manufacturers like Geiger Pump & Equipment (based in Maryland—a nod to your area) include Limitorque among the key brands they sell and service.
Product Lines & Applications
1. MX Series (Smart Multi-turn Electric)
- Debuted in 1997 as the first truly "smart" electric actuator.
- Offers features like absolute encoder, self-diagnostics, local display, SIL safety capabilities, and network connectivity (Modbus, HART, PROFIBUS).
- Handles torque ranges from ~27 Nm up to 2304 Nm.
- It fits both direct-coupled valves and rising stem processes via optional gearboxes.
2. QX Series (Quarter‑Turn Smart Electric)
- It utilizes the same innovative technology as MX but is specifically tailored for ball, butterfly, plug valves, anddampers.
- Features a space-saving handwheel and brushless DC motor, wide voltage range, solid-state control, and torque sensing.
3. L120 Series (Heavy-Duty Multi‑Turn)
- Nine sizes cover torque needs of up to 81,000 Nm and thrusts of up to 2,224 kN.
- Combines with gearboxes (HBC, WG, B320, MT, LB) to serve diverse valve types.
- Available in weatherproof, explosion-proof, and submersible versions—ideal for extreme environments.
4. SMB/SB Classic Series (Legacy Workhorses)
- In service since the early 1960s.
- Rugged cast‑iron body withstands extreme cold in Alaska, Middle East deserts, and nuclear power facilities.
- Delivers torque up to 81 000 Nm and thrust up to 2,224 kN.
- Meets IEEE 384, 323, 344 standards for nuclear safety.
5. Fluid‑Power Actuators (Pneumatic & Hydraulic)
- Models like LPS, TriVAX, and LRP handle cylinder-operated quarter-turn control valves.
- Provide failsafe actions, fast response, high torque, and SIL-rated shutdown protection.
Real‑World Use Cases
- Nuclear facilities deploy SMB units for unmatched reliability in steam feed and safety valve control.
- Oil fields utilize QXM actuators to regulate choke valves and upstream shutoffs precisely.
- Water treatment plants, often located in remote areas, benefit from L120's weatherproof and submersible configurations.
- Petrochemical pipelines integrate MX and QX smart units with HART or Modbus for real-time diagnostics and networked control.
Mead O’Brien proudly serves as an authorized Flowserve Limitorque Blue Ribbon Service and Parts Center, delivering expert support across the Midwestern United States. With decades of experience in valve automation and flow control, Mead O’Brien offers factory-certified repairs, genuine OEM parts, and startup assistance for the complete line of Limitorque actuators. Their commitment to technical excellence, rapid response, and long-term customer partnerships has made them a trusted resource for power plants, water treatment facilities, and industrial sites throughout the region. Backed by Flowserve, Mead O’Brien ensures Midwestern industries get the performance, reliability, and service they need to keep operations running smoothly.
https://meadobrien.com
(800) 874-9655
