Scroll Compressor head wear

[waregl82]

I have a senior tech. at my company who believes that scroll head wear, producing micro metallic particles, which are not stopped by the liquid drier, and will eventually clog the TXV. Does anyone believe this thoery, or heard it, or actually seen it in the field.

Very curious what others think.

[SBKold]

I don't see how the small particles can get through the drier but clog up a txv .

If they are small enough to get through the drier than it would also get through any kind of screen or orifice. IMO

Eventually living in the compressor oil sump.

[waregl82]

thanks for the opinion.

[jayguy]

I have a senior tech. at my company ...

and he is the 'senior' tech???

[ryan1088]

First I'd have him explain to me how a scroll compressor has a "head" then we can go from there. I also don't buy it.

[billygoat22]

I assume by head he means the two scrolls.I've wondered that myself, and believe brought up on this site before.

Scroll compressors supposedly wear in as opposed to piston rings and valves wearing out, that implies wear and particulate.

awhile back some manufs had brown stuff jamming the moving parts in txvs. My theory is that some very fine material plus a little moisture in system resulted in the brown stuff in txvs (rusty sludge). Moisture does tend to freeze up at metering devices when there's enough, right?

other than that, couldn't say.

I would add, that I have seen jammed up txvs on system where the oil was silver gray colored,and some working systems as well, and f/ds in system.

[waregl82]

By "scroll head" I mean the stationary and orbiting scrolls. Sorry for the weak terminology. Hey Billygoat22, when you mention "silver gray" oil, do you believe that metal particulate is creating that color. Also, what does f/ds stand for. Still getting used to the site terminology.
Thanks

[ryan1088]

He meant filter drier. I've pulled metal out of txvs and driers before but most of the time it had been the result of a failure of some kind. We have some people that don't do the best system cleanups after changing compressors or other system components. Next time be sure to get pictures.

[wolfdog]

The scrolls don't touch.

[billygoat22]

As far as the gray oil- I can only assume very fine iron powder, could just as well be anything else, but the few I've seen were only on scroll systems.

[carmon]

I hope he was drunk when he made that statement...........

[billygoat22]

http://hvac-talk.com/vbb/attachment....&thumb=1&stc=1

can't see to well, but the gray on this acid test is from the gray oil.

this unit had a bad compressor- ran in vacuum/ low pressure due to bad txv on evap coil and burned out comp motor- melted blanket and wires to side of comp.

not sure what happened first in this unit.

[wolfdog]

I hope he was drunk when he made that statement...........

I'm not sure whose sobriety is in question...

Let me qualify my earlier statement. The scrolls do not ride against each other like a bearing. Depending on manufacturer, they will rouch at several points in a 360 degree rotation or they do not touch at all and oil makes the seal.
So the chances of metal coming from the scrolls is minimal.

http://www.docs.hvacpartners.com/idc.../811-20065.pdf