cascade systems

[GHAZ]

Hello every body just need some advice. working on a cascade system temperature down to -85C.The refrigerants are R23 and R404A. The low temperature system has an oil seperator which returns oil back to the crankcase,But idon,t trust oil seperators to be that effiecent. So is it wise to add pentane to system to aviod wax forming in the expansion valve and giving the compressor better chance of survival . Greatful for any ideas

[thebigcheese]

we do alot of low temp work, we add it to stop the oil freezing