We have used N2 as a blanketing agent in some applications of our business by connecting flexible hoses between pressure regulators, mounted on high pressure N2 cylinders, and receiving containers fitted with threaded connectors. Since our containers were for the storage of various vehicle fuels, to determine acceptability of the inert gas blanket, we tested for the displaced concentration of flammable vapors released thru the tank vents. In larger tanks of 1000 gallon and more, we used dry ice as a blanketing means and again tested the vented vapors. For hoses we made our own by purchasing reels of welding N2 hoses to which we crimped on connectors.

Since I have never dealt with Bisphenol A, I have no idea as to the reason for blanketing this product stored in RR cars unless this safety procedure is mandated, therefore, there should be some requirements about the needed N@ concentration which obviously would have to be tested at the vents. It stands for reason that the vents need to be as remotely located from the point source of the N2 gas and that there is no contamination issue between hoses and product. There should be no need to lubricate the connectors also.

I should also mentioned that if your operation is a continual one, you may want to check into bulk storage of N2, however, discuss with the supplier the requirements associated with this type of set up. Our operation had to be flexible since it was sporadic and conducted in different job sites.