"Ignoramus2810" wrote in message
...
On Thu, 03 Mar 2005 17:08:32 -0600, Jon Elson
wrote:


Ignoramus2810 wrote:

On 3 Mar 2005 13:59:36 -0800,
wrote:


Mid-range is a belt drive with an oil-filled compressor, these have
alloy pumps with iron sleeves. I've also seen a direct drive with the
same features, I wasn't able to find a motor plate with the speed,
though.

High-end is the all-iron pump with belt drive, these tend to be on the
heavy end for portable operation, you aren't likely to sling one into
the back of a pickup single-handled.



Stan, how can I tell a mid-range unit from a high-end unit by just
looking at them? I am curious if my Curtis compressor is high end or
midrange, according to your description.


If it has an oil pump (sure giveaway is if there is an oil pressure
gauge or oil filter) that is one big sign.

I do not think that mine has that.

Another is if it has unloaders on the cylinder head.

Yes, I have unloaders for easy start.

Not the type he is describing
here is a "high-end" model pump
http://quincycompressor.com/products...qr25/index.htm

William...



These are generally diaphragm-operated, and hold the intake valves
open while the motor is spinning up. Some also have an interlock to
unload the compressor if the oil pressure fails. Disc valves are
another high-end design feature, but it is pretty hard to tell the
valve type from the outside.

Thank you! By the way, the whole pump seems to be made from iron.

i