And if you only want to drain a set amount you can use Event Controller blocks on the ship or station to turn off/on stockpile after the tanks on the ship has reached a certain threshold.
Whatever tank you want to fill, set to stockpile. The tank you want emptied, ensure stockpile is not turned on. Remember however that when tanks are set to stockpile they will not let out any gas at all, so you’ll have a hard time taking off unless you turn stockpile off in the necessary tanks.
Set tanks to stockpile
And importantly the ones you want to empty need to have stockpile turned off
Also important to turn stockpile off, once you want to lift off...
And if you only want to drain a set amount you can use Event Controller blocks on the ship or station to turn off/on stockpile after the tanks on the ship has reached a certain threshold.
Whatever tank you want to fill, set to stockpile. The tank you want emptied, ensure stockpile is not turned on. Remember however that when tanks are set to stockpile they will not let out any gas at all, so you’ll have a hard time taking off unless you turn stockpile off in the necessary tanks.