Don.
If we leave out the saddletanks in the fuel bunker configuration where the saddle tank Kingstons are shut all the time, the saddletank Kingstons in ballast configuration are normally open as for the MBT 3 during war patrol. The Kingstons are time consuming to operate, and you want to be able to dive quickly.
As I mention previously in the RN English we usually call all the MBT floodvalves for Kingstons, including the saddletanks floodvalves, so if you choose to use RN submarine English in you Skizzenbuch, I guess you should use that nomination. Otherwise sometimes Kingston were used in surfacevessels for several hullvalves, but for submarines only for MBT floodvalves.
I usually use MBT 3 with space but cannot guarantee this is 100% correct. Anyhow in order to prevent confusion stick to the same language throughout the whole book being aware that the US submarine language is most probably deviating to some extent from the RN English.
Tore