oil in Disco reservoir

[student1946]

If I get synthetic oil in my reservoir when charging my Disco with co2 will I have to flush my reservoir when I switch to compressed air, or will the co2 flush the oil out as I shoot the gun down and then use the de-gasser tool?I am used to adding a drop of pellgun oil or paintball gun oil when I charge my co2 guns,but I don't want my Disco(or my bod) to be damaged by my ignorance.If i need to flush, what is the recommended method.

[PeakChick]

You must avoid any combustible in the reservoir of your disco. HPA in a PCP and any combustible in the reservoir is a possible recipe for disaster (read explosion).

[melloroadman]

You should only use silicon grease or oil around high pressure air . And very sparingly at that .Marvin

[D R Greysun]

A small amount of oil in the tube of a Discovery is not a problem.  Too many ppls. don't seem to know the difference between HPA and HPO2. Do to ignorance they choose to error on the safe side. Oil in HPA in a 'driver's tank' is bad, (make that deadly) 'for your lungs'. Hydro-carbon and HPO2 is a bomb so the two should never come in contact.

D R

[shearload]

I've been toying with an idea of a relatively inexpensive setup for charging my Discovery and other PCPs (as I add to the arsenal).  However, there will be a risk of introducing an oil vapor into the Disco's reservoir.

Air-driven high pressure pumps are relatively inexpensive.  I have several from other projects; the Haskel pump I have in mind has a 36:1 ratio; that is, 100 psi compressed air supply will result in a 3600 psi output.  This pump was intended to pump oil, or something similar.  I could transform the high-pressure oil into high-pressure air by pumping oil into the bottom of a high-pressure cylinder and taking high-pressure air out the top. After charging the rifle, a valved return line and residual cylinder pressure could return the oil to the reservoir, ready for the next charging operation.

However, because of the direct contact between the air and oil at elevated temperature, there's a good chance that oil vapor would end up in the rifle reservoir.  I could use non-flammable hydraulic oil, but worry about the effect of ethylene glycol on various parts of the rifle.

I know Haskel and others make pumps for gases,  too.  But they cost a lot, and I don't already have one.  And I know that some hydraulic accumulators separate the fluid from air using bladders or pistons.  But I don't have one of those, either.

I'll let you know how it turns out.

[kiwi]

So..what you are saying...talking about is a - air over Hyd pump ?.....and you intend to convert it into a- Hyd over air ? ...

Now...what about the recycling vavle system /shutle valve in them...how will / could it work with oil  instead of air? ...

Why not convert it into a air over air??????

If you did go the Hyd over air way... use a oil like  "Shell Telus 32"  that will not combust....

?? or are you thinking of some other type of pump ??

the idea is more than possable

Pete

[shearload]

Yes, these pumps are sometimes called air-over-hydraulic pumps, and are found on lots of equipment nowadays.  They are often available as used or surplus for about $100 US.

I don't intend to convert the pump; I doubt that the machining tolerances or seal design will allow it to pump air directly to the needed pressure, and the pump isn't designed to dissipate the heat generated when compressing a gas.  I intend to pump oil, as it was designed.  I have a compressed air system at home regulated at about 100psi.  I have a high-pressure cylinder of sufficient size, I think (about 2 liters).  By my rough calculations, if I precharge the cylinder with 100psi air, then begin filling it with oil, there should be sufficient air pressure to charge the Disco when the cylinder is about 90% filled with oil.  I need to know the internal volume of the connecting air tube to the rifle reservoir for more precise calculations.

I looked at the specifications for Shell Tellus 32; it seems to be petroleum based, with a flash point of 209 C; even if it didn't combust, that's low enough to produce vapors during charging, I'm afraid.

[melloroadman]

Take a look at this compressor oil . Chem lube .Marvin
http://www.protecair.com/

[kiwi]

shearload - 6/12/2009  11:13 AM

Yes, these pumps are sometimes called air-over-hydraulic pumps, and are found on lots of equipment nowadays.  They are often available as used or surplus for about $100 US.

I don't intend to convert the pump; I doubt that the machining tolerances or seal design will allow it to pump air directly to the needed pressure, and the pump isn't designed to dissipate the heat generated when compressing a gas.  I intend to pump oil, as it was designed.  I have a compressed air system at home regulated at about 100psi.  I have a high-pressure cylinder of sufficient size, I think (about 2 liters).  By my rough calculations, if I precharge the cylinder with 100psi air, then begin filling it with oil, there should be sufficient air pressure to charge the Disco when the cylinder is about 90% filled with oil.  I need to know the internal volume of the connecting air tube to the rifle reservoir for more precise calculations.

I looked at the specifications for Shell Tellus 32; it seems to be petroleum based, with a flash point of 209 C; even if it didn't combust, that's low enough to produce vapors during charging, I'm afraid.

Ok..Now that a pretty kool idea....put a piston between the air / oil..
or use a bladder inside the pressure chamber to keep the air & oil separate