Product - SC/VH Hydraulic Linear Actuator
​​​​​​IMI STI’s hydraulic linear piston actuators are designed to drive on/off and control valves for the most demanding applications in the Power and Oil & Gas industries; such as choke, gate, globe and wedge valves.
Thanks to the rugged and reliable design SC/VH actuators ensure smooth and precise valve operation without any maintenance for the whole operating life, even in the harshest of environments.

​Key features

  • ​Several sizes available from 30mm to 300 mm or larger if required
  • Several stroke options available
  • Double acting or spring return design
  • Manufactured in carbon steel material without any cast/grey/ductile iron or aluminium parts
  • Full stainless steel design available for both double acting and spring ​return actuators
  • Action inversion without tubing inversion only for ND 1/4” version
  • Electroless nickel plated cylinder to minimise friction and prevent corrosion
  • Multiple lifting lugs ideally located to balance centre of gravity for safe lifting
  • An integral or declutchabl​​e manual handwheel or hydraulic hand pump available on request
  • Customised valve bracket, open or close design on request
  • Quick connection solution for valve adaptation available on request


Maximum safety is ensured by the design of spring packs as spring compression is independent from removal of cylinder cap and tie rods.
The compact design means the actuator is not sensitive to vibration and external loads.
Double guide for piston, bushing and heavy-duty nickel plated cylinder ensure safe and reliable operation.
Designed to provide high performance with minimum space and weight.

Technical specifications

​Operating pressure
Up to 350 barg

Certifications and approvals
PED 2014/68/EU
ATEX 2014/34/EU
IP66/67M according to IEC/EN 60529

Standard operating temperature
-30 °C to +100°C (lower or higher temperature on request)

Standard supply medium
Hydraulic oil
Fire resistant fluid version on request​

​Product breakdown

Optional accessories

IMI STI designs and produces a wide range of accessories and control systems to ensure superior performance and to satisfy the most demanding requirements in modulating, on/off and heavy duty service. Control systems panels/cabinets can be installed on the actuators or supplied separately for remote mounting which allows for easy access and to limit exposure to excess heat and vibration. For more information, see our dedicated accessories brochure or visit​

Latest News

Valve Doctor programme celebrates 20th anniversary
16 September 2019
Unconventional support for the unconventional oil and gas industry
01 July 2019
17 June 2019
IMI CCI showcases choke valve at DUG Rockies conference
04 June 2019
Jackie Hu appointed Divisional Managing Director of IMI Critical Engineering
07 March 2019
Roy Twite to succeed Mark Selway as Chief Executive of IMI plc
05 March 2019
IMI Critical holds Safety Summit
21 September 2018
New HSE handbook to help keep field service engineers safe
10 August 2018
Safety first at IMI Critical
31 July 2018
IMI InterAtiva’s Series RK Valves certified ‘fire-safe’
24 July 2018
IMI CCI participates at regional VPP Safety Summit
08 June 2018
Largest Romanian customer recommends IMI Remosa
10 May 2018
Lean success in IMI Critical back office functions
04 May 2018
Isolation valves adapted for Fluidised Catalytic Cracking applications
30 April 2018
IMI Critical Korea closes in on world-class LEAN performance
27 April 2018
IMI board tours IMI Critical businesses
25 April 2018
New positioner software tools from IMI STI
08 February 2018
Launch of Zero Backlash Scotch Yoke Mechanism
16 January 2018
IMI Critical Korea certified to sell actuators in Europe
20 September 2017
IMI Critical named ‘supplier of the year’ by Korea’s Doosan
19 September 2017
100th Valve Doctor graduates from IMI Critical
13 September 2017
Top HSE certification for IMI Critical’s California site
12 September 2017
Launch of High Endurance Actuator
21 April 2017
Launch of AB6350 valve
06 April 2017
Launch of 100DPC Multi-trim
17 March 2017
Launch of 840GS control valve
22 December 2016
IMI Critical to exhibit new technology at ADIPEC 2016
25 October 2016
New graduates join IMI Critical in four countries
22 September 2016
IMI Critical to take stand at ONS 2016 in Norway
16 August 2016
IMI Critical opens new China plant in Qingpu
27 July 2016
IMI CCI Korea celebrates 2,000 days of no “Lost Time Accident”
25 July 2016
Visit to IMI Z&J Germany by the Russian Economic Bureau from Bonn
11 July 2016
IMI Z&J Düren moves into modern offices
08 July 2016
IMI Critical Engineering forms strategic partnership with MRC Solberg & Andersen
05 April 2016
IMI Way Day 2016 date announced
01 March 2016
NEW IMI Eye – fourth edition
26 February 2016
IMI Critical co-locates China businesses
20 January 2016
IMI CCI Switzerland gains certification for new generation safety valves
18 December 2015
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
23 November 2015
IMI CCI Sweden secures new contracts on three continents
23 November 2015
IMI Critical Engineering appoints new petrochemicals head
05 November 2015
IMI CCI Czech Republic gains ‘Safe Enterprise’ certification
03 November 2015
IMI Critical announces 90mRMB investment in China
29 October 2015
IMI CCI SriCity wins regional safety award
27 October 2015
Key clients attend grand opening of new Aberdeen facility
23 October 2015
IMI companies ‘act as one’ to deliver for customer
02 October 2015
IMI CCI Sri City approved by NTPC
01 October 2015
IMI Critical Engineering showcases innovation at Valve World Expo Asia
28 September 2015
Nexen awards IMI Orton
25 September 2015
IMI Critical Engineering celebrates opening of new Jubail repair centre
23 September 2015
IMI Critical and IMI Precision join forces at Valve World Expo + Conference Asia 2015
21 September 2015
IMI Critical Engineering opening of new Jubail Repair Centre
18 September 2015
IMI CCI India manufactures first 1050MW turbine bypass valve
20 May 2015
Largest ever contract for IMI Critical Engineering
18 February 2015
New Houston facility opens
12 February 2015
IMI Critical completes acquisition of Bopp + Reuther
02 January 2015
IMI Critical takes family of brands to Valve World 2014
11 December 2014
IMI STI doubles size of Italian plant
20 October 2014


​Global sales
Product - SC/VH Hydraulic Linear Actuator