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changing o-tubes again

Turbo on Wed July 16, 2008 6:44 PM User is offline

I am having some trouble understand the effects of change a white gm o-tube to a blue tube. If someone can give me an understanding. It will be greatly appreciated. I understand the white is a larger orifice so it allows more freon past so if we had the same conditions the white will have a higher low and higher high compared to a blue. If the orifice is smaller the gas will have more time in the condenser so it will lower the high side. Now how small can you go before you are not able to keep the evaporator flooded. If you go too small then it will take a lot of pressure on the high side to get the evaporator flooded. Does this mean a system which was designed for a white would need more freon when you put a blue in. I am sorry for my babble but I am trying to understand the theory here. Can some please explain.
Thank You

JJM on Wed July 16, 2008 11:57 PM User is offline

I assume this has to do with an R-12 to R-134a conversion? The Ford blue at 0.067 is just a better "fit" with P/T differential between R-12 and R-134a than the GM white 0.072. Don't overanalyze this, just use the Ford blue on a retro and you should be fine.

Remember the OT is an "expansion device" in the system.


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