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hydraulic actuator fail safe action as fail last

HI

we have a hydraulic actuator installed at our site which we want to modify to have the fail action position as fail last, for both power failure and hydraulic failure. I see there are two options for power failure case, option one is to keep the actuator full of hydraulic (two hydraulic operated pilot valves for open and close as normally open, meaning hydraulic keeps flowing to actuator during power failure) and the other option is to cut the hydraulic supply to the actuator during power failure, through the closing of pilot valves. My question is , is there an advantage of one option over an another and which one I have to go for ? 

Thank you for your comments  

john

• 4 Jul 2021 2:06 AM
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4 Replies

• Hakon Espvik

  

  • 9 Jul 2021 12:26 PM

  John,
  
  Would you be able to provide more information on the actuator you have a question about? Brand/model/serial number would allow me to better answer your question.
  
  Thank you

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• john

  

  • 11 Jul 2021 9:40 AM

  In reply to Hakon Espvik:

  Hi Hakon
  
  Thank you for you message. Actuator is bettis G13-DA.

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• Hakon Espvik

  

  • 13 Jul 2021 5:24 PM

  In reply to john :

  John,
  
  We would be able to better advise if we had a serial number to understand the controls on this actuator. Based on the information provided and assuming I understand you question correctly, option 2 in which you cut the hydraulic supply would be the preferred method.

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• Hakon Espvik

  

  • 13 Jul 2021 5:24 PM

  In reply to john :

  John,
  
  We would be able to better advise if we had a serial number to understand the controls on this actuator. Based on the information provided and assuming I understand you question correctly, option 2 in which you cut the hydraulic supply would be the preferred method.

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