SSV/USV Actuator : The device which causes the SSV/USV valve to open when power is supplied and to automatically close when power is lost or released. (RP 14H, Spec 14D)
The Mudblogger (Oilfield, Energy and Related Photographs), Oil Field Glossary, TX, USA 2014. http://mudblogger.com/oilfield-glossary/, (Oil - Amer) {777}