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SMB Series

Flowserve Limitorque SMB actuators are designed and built to provide years of dependable service in a wide range of environments.




Petroleum production and refining, sewage collection and treatment, tank farm transfer, water supply and distribution (water), boiler circulation, nuclear service, desalination, filtration, gas production, heavy oil, oil sands and shale, molten salt transfer, decoking


Mining, oil and gas, power generation, wastewater collection and treatment, water supply and distribution, water treatment, nuclear power

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From the extreme cold of the Alaskan North Slope to the extreme heat of North Africa and the Middle East, SMB actuators perform reliably year in and year out. For critical or demanding service conditions, trust the industry standard of excellence — SMB.

Whether direct-mounted to multi-turn valves, dampers or sluice gates, or side-mounted to HBC or PT worm gear reducers for quarter-turn applications, Limitorque SMB actuators deliver unsurpassed performance.

Introduced in the early 1960s, the SMB and the spring-compensated SB actuators for high-speed and high-temperature service are at work for the U.S. Navy, every nuclear power generating facility in the USA, and virtually every other industrial environment. With a rugged cast iron housing and precision-machined gearing, the SMB and SB actuators embody sensible design and solid construction.


  • 50+ years of installed history
  • Unmatched durability, dependability and flexibility
  • Torque output to 60 000 ft-lb and thrust output to 500 000 lb
  • Fully qualified for nuclear applications to IEEE 384, 323, and 344
  • Weatherproof, explosion-proof, and submersible constructions

Call us today at (708) 388-3232

24-Hour Emergency Service

Our associates are available when you need them. We can respond by providing emergency parts, machining, or on-site technical expertise. We specialize in servicing actuators, that have malfunctioned electronically or mechanically, causing system shutdown or redirection. We aim to get you back in business as soon as possible.

Call our 24-hour line at (630) 989-3231