Good morning...

I need to purge cases [assume 20-100 ft3] with Nitrogen to preserve them in storage at customer sites where they are exposed to all sorts of moisture sources.  We essentially want to mount a N2 bottle on the casing or on a stand next to it and keep it purged.

The key is that I do not want to try and seal up the casing and all of its associated connecting piping and tubing to a high pressure.  I just want to hold some extremely low minimum pressure so any leakage will be out of the casing...not back in.  

Can anyone help with specifics of a bottle/regulator/monitor that I could do this with.  A few other key points...

1.System will be used for up to a year or two and then frequently just get scrapped.  I do not need anything fancy or beautiful...translation expensive...just workable.

2.I want the pressure in the inches of water area...or even lower if practical.  Any positive pressure I can control to...the lower the better...will do what I need and minimize leakage.

3.I would look at sourcing components separately...or...buying a kit that is commercially available or can be built for us custom.  We need 10-20 of these per year.

4.We have little to no experience controlling to the low flows and pressures.

Thanks in advance.

Regards,

Barry

Millions of phone cables around the country have this exact setup. You see a nitrogen bottle strapped to a telephone pole with a regulator on it.  You would want the same setup.  I'm not sure what regulator they use but you could find one and look at it, or ask a phone guy.

Keep in mind that if your setup is in an enclosed space you will need to follow certain rules as that could result in a fatal accident.  Nitrogen does not support life and so the space could end up with an oxygen level below those that can sustain life.

Keith Cress
kcress - http://www.flaminsystems.com

The main issues are:

>  You have not specified the leak rate of the containers.  The pressure requirement is irrelevant if your containers leak.  A typical gas bottle contains about 450 cubic feet of STP nitrogen.  For a two-year span, that equates to 0.22 cc/s, which is a pretty tiny leak.

> The gas bottles I alluded to are pressurized at 4500 psi, not something that you want accessible to ANYONE over a two-year hiatus.  An accidental encounter with a forklift could send the bottle on its merry way, wreaking havoc and destruction.

Seems to me that you'd be better served by a one-time purge with nitrogen and filling the containers with dessicant.

TTFN

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