Basically people usually use the oil on the tip of 12 gram cartridges to be able to remove them after the gas is spent. It wont hurt it if you do for your peace of mind There isnt too much to lubricate in the system...basically if you put some oil (a little) in the valve before you installed the PN tank I think you would be good to go for a good while. Just my opinion others may vary.
John
The 850 Resource