The difference among SXV, XV, TV, PV, FV and other valves used in oil refinery.
FV/FCV: A flow control valve regulates the flow or pressure of a fluid.
PV/PCV: Pressure control valve
LV/LCV: Level control valve
TV/TCV: Temperature Control valve
SXV/UV: are usually on/off a type of valves used for full open or full close position. Normally, they are used for ESD system.
XV (On-off valves): They are used for normal isolation of any equipment in a process plant.
AOV: Air Operated Valve
HV: Hand Valves, controlled manually as per the requirement to control the parameters. Dampers of furnaces are operated manual and are tagged as HV. They don’t work on Auto Mode.