Title: Siemens STA73-eng (1).pdf
Valve is closed without actuator (Normally closed) • The valve stem is fully extended • Example: Small valve V..P47..Most third-party valves are NO valves.Valve and actuator combinationNO function • STA.. actuator stem is extended when de-energized.NC valve required.NC function • STA.. actuator stem is extended when de-energized.NO valve required.