I don't know the designation used in other countries, but in the oil and gas industries that I have worked for, SDV designation is used for Shut Down Valve. This is also in accordance with API-14C, Table 2.1
For Shut off valve, the first thing that came to mind is tight shut-off valve. These are basically manual valves in which 2 valves can be installed in a line to provide tight shut-off when the line is not in service.
I stand to be corrected.