Currently, we are installing a boiler system for our coating line. The process requires a 220 gallon compression tank. The system design calls for nitrogen filled tank. The factory noted that the tank needed to filled in the field; thus, my question is what is the official nitrogen filling method for the compression tank?? I recall that standard practices are as follows Purge, Fill with water, pressurize with nitrogen to required pressure; please let me know your thoughts on this and I am very grateful for any advisement on this matter. Thanks.