​​​​​​​​​​​​​​​​​​​​​​​​IMI STI is an international leader in valve actuation. 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, smart and traditional positioners, and a full range of accessories. ​

Critical applications​

  • Power
    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. 

  • LNG
    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. 

Key technologies

  • Linear actuator (SC series)
    Our pneumatic valve piston actuators and damper actuators are purpose designed and manufactured for the operation of flow control devices such as dampers, louvers, butterfly and ball valves. They are ideal applications for power plants, refineries, pipe steel works and on board vessels.

  • Quarter turn actuator (RT series)
    Our RT Series offers a complete range of pneumatic and hydraulic quarter turn actuators suitable for all on-shore and off-shore applications, covering the general on-off valve and modulating control valve duties.

  • Control drive actuator (CM series)
    This pneumatic actuator system guarantees continuous operation in harsh environments; it is used in power stations, steel industries, petrochemical plants, desert areas, among others.

  • Positioners (PT series)
    We offer a wide range of positioners: pneumatic or electro-pneumatic, smart (very high flow rate) or 'traditional type'.

  • Accessories (AC series)
    A full range of accessories and control systems is available.

Aftermarket services

Fast delivery, with 24 hour spare parts shipment service, on site Field Service for spare parts installation and upgrade and regular maintenance of our actuator and accessories. Our spare parts service guarantees original equipment parts are interchangeable with existing ones. We provide training on site for better calibration and knowledge of our system and upgrade service. ​​

IMI STI - Model 231 requirements

In order to render the organization, management and corporate control system compliant with the Legislative Decree, June 8, 2001, n. 231, the company adopted by resolution of the Board of Directors on 19 July 2013, the organization and management model required by Legislative Decree, June 8, 2001, n. 231 (hereafter, the "Model 231") and appointed a Supervisory Board with the task of monitoring the proper implementation of the Model 231.
The Model 231 has been updated over time (lastly, on October 31, 2014) and integrated to reflect the subsequent adoption of legislation, which has expanded the category of crimes covered under the umbrella of the administrative responsibility pursuant to Legislative Decree, June 8, 2001 n. 231.
The contents of the Model 231 are consistent with the provisions contained in the guidelines adopted by industry associations and the Model 231 represents a further step towards strictness, transparency and sense of responsibility in internal relations and relations with the outside world, while offering shareholders the best guarantees of efficiency and compliance to the law.
The chairman of the Supervisory Board is Mr. Ermelindo Lungaro.
Any violation to the regulations and to the compliance of the Model 231 must be reported to the Supervisory Board.
Reports may be submitted in the following manner:
Writing to:
STI S.r.l.
Supervisory Board
Att. Mr Ermelindo Lungaro
Via dei Caravaggi, 15
24040 - Levate, Bergamo (Italy)

Data Privacy

STI S.r.l. (IMI STI) is aware of the importance covered by the Protection of Personal Data and undertakes to  respect  the  rules  of  conduct  set  up  by  the  Legislative  Decree,  30  June  2003,  n.  196  (Code regarding the Protection of Personal Data), which are to guarantee navigation in a secure network, through Personal Data Protection.  
Attached please find the Privacy Disclaimer under Article 13 of the Italian Legislative Decree, 30 June 2003, n. 196. 

IMI STI - Modello 231

Al fine di adeguare il sistema di organizzazione, gestione e controllo societario al decreto legislativo n. 231/2001, la società ha adottato con delibera del Consiglio di amministrazione in data 19 luglio 2013 il Modello di organizzazione e di gestione previsto dal Decreto Legislativo, 8 giugno 2001, n. 231 (di seguito, “Modello 231”) e ha nominato un organismo di vigilanza con il compito di verificare la corretta osservanza del Modello 231.
Detto Modello 231 è stato nel corso del tempo aggiornato (da ultimo, il 31 ottobre 2014) ed integrato in relazione agli interventi legislativi succedutisi negli anni, che hanno ampliato la categoria dei reati presupposto della responsabilità amministrativa ex Decreto legislativo, 8 giugno 2001 n. 231.
Lo stesso è coerente nei contenuti con quanto disposto dalle linee guida elaborate in materia da associazioni di categoria e rappresenta un ulteriore passo verso il rigore, la trasparenza e il senso di responsabilità nei rapporti interni e con il mondo esterno, offrendo al contempo agli azionisti le migliori garanzie di una gestione efficiente e corretta.
Il presidente dell’organismo di vigilanza è il signor Ermelindo Lungaro.
Ogni violazione delle norme del Modello 231 deve essere riferito all’organismo di vigilanza.
Le segnalazioni possono essere presentate nel modo seguente:
Scrivendo a:
STI S.r.l.
Organismo di vigilanza
Att. Sig. Ermelindo Lungaro
Via dei Caravaggi, 15
24040 - Levate, Bergamo

Protezione dei dati personali

STI S.r.l. (IMI STI) è consapevole dell’importanza della tutela dei dati personali e si impegna a rispettare le regole di condotta sancite dal decreto legislativo, 30 giugno 2003, n. 196 (Codice in materia di protezione dei dati personali) dirette a garantire una navigazione in rete sicura attraverso la tutela dei dati personali.
In allegato l’ Informativa Privacy ai sensi dell’art. 13 del decreto legislativo, 30 giugno 2003, n. 196.

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IMI Critical co-locates China businesses
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IMI Critical rise to Dragon challenge
30 November 2015
IMI STI achieves CRCC approval for new products
24 November 2015
IMI Truflo Marine Attend the Engineering Technology and Innovation Exhibition 2015
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IMI CCI Sweden secures new contracts on three continents
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IMI Critical Engineering appoints new petrochemicals head
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IMI CCI Czech Republic gains ‘Safe Enterprise’ certification
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IMI Critical announces 90mRMB investment in China
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IMI CCI SriCity wins regional safety award
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Nexen awards IMI Orton
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IMI Critical Engineering celebrates opening of new Jubail repair centre
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IMI Critical and IMI Precision join forces at Valve World Expo + Conference Asia 2015
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IMI Critical Engineering opening of new Jubail Repair Centre
18 September 2015
IMI CCI India manufactures first 1050MW turbine bypass valve
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Largest ever contract for IMI Critical Engineering
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New Houston facility opens
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IMI STI doubles size of Italian plant
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