We all worry about our PCP's getting the purest and the driest air possible for fear of corrosion. Two things cause corrosion, water and oxygen. Air is composed of about 78% nitrogen, 21% oxygen and 1% other gases as well as water vapor. The solution is staring us in the face, NITROGEN. Compressed nitrogen is used in welding and other industrial uses. It is made to be as pure as possible and completely free of water. Nitrogen is very nonreactive to metals, whereas oxygen is very reactive and causes rust among other types of corrosion. Oxygen can cause explosions in areas that contain volatile hydrocarbons such as lubricants, yet we go about pumping air into our tanks and guns at pressures of up to 4500 psi in the presence of oxygen. Hmm! I have a degree in chemistry, and possibilities like these bother me. When I see air-gunners squirt flammables into the breach of break barrels to cause dieseling I cringe. So I think we need to share the details and specifics of how nitrogen can be used. I personally have not set up to use it, but I plan to do it. This forum is great for helping all of us by sharing our successes so the we all don't have to reinvent the wheel. So I look forward to the time when we don't have to worry about water getting into our guns and can use green fill port caps to indicate that we are using nitrogen (like the green valve caps on tires filled with nitrogen). Love to hear from you N2 experts!