Re: bomb recharge procedure???

[Phil and Judy Rose <pjrose@servtech.com>]

>> There is a line of Schrader-type valves that handle these pressures, and
>> more.  All of the hydraulic system accumulators on the CNC machines where I
>> work are recharged via this sort of valve.  Some are charged to over
>> 4000psi.  The valves don't look like anything special, just like an
>> all-metal tire-filler...the charging rig uses a thread-type clamp you screw
>> onto the valve, then a separate valve depresses the core for pressure
>> checking or system pressure tuning...BTW, these accumulators are a *lot*
>> bigger than an Audi bomb...
>
>Can't say I'm surprised.  There is already a valve inside the bomb that
>can handle that pressure, albeit hydraulic oil, not N2.  And the
>whole hydraulic system up to the servo runs at that pressure,
>so controlling 2000psi isn't that difficult!

I'm trying to be optimistic, but let's not equate the ability to "control"
2000 psi hydraulic fluid for periods of hours with controlling the same
pressure of nitrogen gas for periods of months. Yep, I know they're both
fluids ;-). I wonder if problems (i.e., leakage) from a valve could be
circumvented by using a firmly tightened external valve-cap with gasket?

So, although there may be simple add-on valves that can retain 2000-4000
psi nitrogen pressure for periods of time adequate to certain applications
(such as CNC machines), the question is "how long?". Will Audi owners (even
Qlisters) be interested in trading a $300-every-5yrs bomb replacement for a
system that needs monthly, or even semi-annual recharge? Annual
maintenance--maybe, depending on the cost-to-charge.

Sorry for the wet-blanket tone. I still think it's worth looking into (and
at the moment it would be lovely to pull my two Audis with dead bombs in
someplace and say "fill 'er up.").

Phil Rose

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