English to French Tech/Engineering Petroleum Eng/Sci digital positioner valve

This term is used in drawing of an element of a digital positioner for sweet gas flow control.
I think this is an electronic term, describing part of a control loop hardware.
I cannot display the use in a sentence and Proz does not allow me to put drawings.
persons that are interested may request a drawing I would be more than happy to provide the images. Two simple drawings ( produced probably by Solidworks but I will provide a jpeg or pdf.
Thank you in advance
regards
Ivan