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IMI STI is an international leader in valve actuation, especially for severe service applications. We design and manufacture complete actuation systems, which can be fully customised to meet customer needs, to operate industrial valves for the most demanding applications and processes. We offer a diverse range of valve actuation products including linear and quarter turn actuators (pneumatic, hydraulic and electro-hydraulic versions), smart and traditional positioners and a full range of accessories.

Fast Facts

  • Founded: 1960
  • Joined IMI: 2002
  • Installed base: 220,000+ actuators
  • Certifications: ATEX; IECEX; ISO 9001; PED (Module H and H1)
  • Locations: Italy

Critical Applications

Oil & gas


Our fast-stroking, highly-reliable actuators have been recognised for providing superior performance in severe service applications for over 50 years. Key applications include turbine bypass systems, steam damper heating, boiler level control (including nuclear), pump recirculation, emergency shut down, line isolation, and dampers for fans.

Oil & gas

In the oil & gas industries, we provide compressor anti-surge (especially hot gas bypass), choke valves, gas to flare and dampers for fans.


Over 90% of compressor anti-surge valves in LNG plants worldwide are fitted with IMI STI actuation control systems, maintaining plant up-time and operational efficiency.

IMI STI engineers at work
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IMI STI actuators and accessories are installed in demanding applications, therefore it is crucial to keep them operating at peak performance levels. IMI STI provides a wide range of aftermarket support services, from web-based spare parts availability to express delivery of components. A team of qualified engineers is available for customer support, including on-site, commissioning, troubleshooting and maintenance activities.

Most of IMI STI actuators are equipped with a diagnostic communication tool to deliver plant operators with information about optimal equipment performance and to ensure compliance to safety and regulatory requirements.

  • Fast delivery of spare parts, 24-hour shipment service
  • Field service on-site for spare parts installation and upgrade
  • Maintenance service on-site
  • Remote customer care telephone assistance
  • Training on-site
  • Upgrade service