Do't worry much about pressure in those tanks inside your house assuming they have a safety relief valve....I have kept my tanks inside my house winters and summers to keep them clean and nice...It is very cold here in the winters - NW Montana and my guns go to the safe unless I can shoot from a window...This is, if the wife allows me!
It was very nice 2 winters ago, I was shooting from inside the house at 68 F ( -30 F outside) while drinking good coffee and listening to good music...I was shooting at least a tin/day but last winter we went south with the snow birds all winter and this year will most likely do it again, so no more shooting from indoors....
I mention this because that bug is "Very Contagious"...You will need to plan a good strategy for the wife to accept you shooting from the bedroom or living room! !
Regards,
AZ