[urq] RE : The "Bomb" possible cure and a question

[Louis_Alain_Richard@computerhorizons.com]

OK now, I see where you are going with that.

Aren't these accumulators the "green spheres" from the DS-SM Citroens ? How
much are they sold in Europe ? I am pretty sure I can find some here in
Canada, there is a huge Citroen garage (with as much of 50 cars in a field)
no far from me.

Beware though, as Citroen used different hydraulic fluids depending on the
model year. The Bombs-spheres for our early urQ cars must used the standard
ATF red fluid, so the sphere's membrane must withstand this type of fluid.
But then, ATF is a "thick" fluid, compared to the "thin" Pentosin CHF-7.1
and CHF-11s, so it might not be a problem with the Citroen spheres.

What type of fluid the Citroen are using ? And what is the operating
pressure of the Citroen hydraulic system ?

Louis-Alain


"Patrick Carlier" <p.carlier at pandora.be> wrote on 2005-08-25 11:22:15:

> You are right offcourse .
> I forgot the Kelvins , and calculated in
> Celsius .
> My university days are also a long time ago .
>
>
> Thx for thinking along .
>
> Pat
>
> ----- Original Message -----
> From: <Louis_Alain_Richard at computerhorizons.com>
> To: "Patrick Carlier" <p.carlier at pandora.be>
> Cc: <urq at audifans.com>
> Sent: Thursday, August 25, 2005 5:10 PM
> Subject: Re: [urq] RE : The "Bomb" possible cure and a question
>
>
> Maybe my chemistry is too old, but my calculations shows an ambient
> pressure of 29 Bar.
>
> To achieve that number, I used the PV=nRT formulae, the Perfect Gases
Law.
> Don't forget that the temperatures in this formulae are to be expressed
in
> Kelvin, not Celcius or Fahrenheit.
>
> The figures are :
> Gas volume is constant, if the accumulator is empty of oil.
> P1 is 32 Bars at T1=313 Kelvin (273K + 40C)
> P2 is unknown at T2=293 Kelvin (ambient 20C + 273K)
>
> From that, considering N2 as a perfect gas, we find
> P1/T1=P2/T2
> then
> P2=P1*T1/T2
> P2=32*313/293= 29 Bar
>
> Am I right ?
>
> Louis-Alain
>
>
>
> urq-bounces at audifans.com wrote on 2005-08-24 15:45:22:
>
> > Datasheet says :
> > Maximum accumulator efficiancy is achieved when the
> > Pre charge pressure at operating temperature equals
> > 0.9* the minimum system pressure .
> > Maximum operating pressure should not exceed 4 times
> > the precharge pressure .
> >
> > So that would be 0.9*36 = 32 Bar at operating temperature .
> > Givven this , ambient precharge pressure can be calculated .
> > What would normal operating temperature be ?
> > My best guess is 40°C/100° F .
> > In that case , ambient preset pressure would be 22 Bar .
> > As for the max pressure of 57 bar , or even 75 bar in a worst case
> situation
> > that is still below 4 times the preset value .
> >
> > Please , any thoughts / comments are welcome
> >
> >
> > Pat