valves valves kali_0142 (Mechanical) (OP) 31 Oct 17 07:03 Hi friends. can anyone tell about unknown technical details about automation valves? RE: valves LittleInch (Petroleum) 31 Oct 17 08:08 No. Are these "known unknowns"?? Needs a lot more information to add anything more. Remember - More details = better answers Also: If you get a response it's polite to respond to it.