Air is 80% nitrogen. Essentially air is dirty nitrogen contaminated with mostly oxygen and water vapor from an hpa airguns pov. With the pure nitrogen, do you get a 4ft tall cylinder full from a gas shop, similar to the arrangement with propane? Or do you have your hpa bottle(s) filled at a shop?
Just got off the phone with the gas supply store. Ez peasy. A 7litre? Tank full filled with nitrogen is less then $300- new tank. $60- to refill. Here's my plan. Fill my 7 litre hpa bottle with nitrogen every other fill. This will keep everything nice and happy.
Every other time just gives you dry once and potentially wet the next time. Once water is in your tank, nitrogen is not going to take it out.
Update. Shortly after this post I added a high quality air dryer from Joe Brancato at Top Airgun. The air/ oil separator on the Omega Air Charger does a good job, but here in southern Vt it gets wicked humid in the summer. A stitch in time saves nine. Thanks for all the helpful advice.
physically impossible to do that, 29.92 inches of Hg. is a perfect vacuum at sea level, same as outer space and reduces with altitude. Sorry just being a little pedantic. Water in your air is the enemy. Pressurizing the intake air of your HPA compressor is an issue, keep the infeed air less than 10 PSI to avoid overloading the pump, pressure on the piston makes starting amperage too high. My shop air has a built in desiccant dryer, that air has a dewpoint around -100 f or thereabouts. I put a male air line QD on the HPA pump and feed it with around 10 PSI of my shop air. So far so good, no evidence of any moisture. Clean dry air is critical to protect your guns. I have considered doing something similar.
Ten Beers and I have been discussing this with regard to filling SCBA bottles. I do not know of a simple way to leave the filter pressurized yet have the ability to connect-disconnect the filter. Compressor side must be bled for compressor to start, by design our 8 mm QD's prohibit connecting or disconnecting under pressure. Gun side must be bled as well. Shuttle type valves can work in low pressure applications. An input check valve on the filter would allow retaining pressure yet allow stopping the pump and bleeding pressure for restarting. That resolves your issue simply. A check valve is a one way only valve, like a diode if you know electronics. Point the arrow on the check valve toward the filter on the input end of the filter. I did a fair amount of pneumatic circuit design in a former life, low pressure (100 PSI) only however. Retired now and the Dyslexia is getting worse...I read this solution through three times.
