Bill Amsterlaw on wed 5 mar 97
The oil in my pugmill's vacuum pump has a milky layer that floats on top of
the oil. Clayart discussions from about a year ago indicated that this
cloudiness comes from moisture collecting in the pump and recommended
installing a device to dry the air before it reached the pump. The pump seems
to be working perfectly well. I tried to find an in-line drying device using
the Grainger online catalog at http://www.Grainger.com searching for
"desiccant" and "drier" but was unable to find the name of a product that
would do the job.
1. Is this situation doing harm to the pump? Is a drier really necessary?
2. What is the exact name of the device?
3. How does the drier work?
- Bill Amsterlaw (firstname.lastname@example.org)
On 12 Mar 1996 Doug Kassebaum wrote:
Watery oil turns cloudy when the mill runs and for a short time thereafter,
before the water has time to settle. Water makes an imperfect seal which will
prevent the pump from its maximum draw. If you have watery oil, replace the
oil and get an in-line drier for the vacuum line. Grainger and McMaster Carr
are two good sources.
On 11 Mar 1996 Cheryl Shoemaker wrote:
The oil in the vacuum pump goes cloudy ... fast because it is so humid here
and my clay supplier has taken to shipping the clay much wetter/softer than in
years past. The fix was a desiccant dryer on the line to the vacuum pump.
Kenneth D Westfall on thu 6 mar 97
The cloudy appearance is caused from moisture in the oil. This is NOT
good for the pump...where there's moisture, there's oxidation and loss of
seal. The long term affect could be rust internally. The short term
affect is lost performance of the pump. Changing the oil periodically as
routine maintenance is my suggestion. All machinces which use oil
utilize the oil as a coolant and a lubricant. The long term affect of
heat on oil is a breaking down of its lubricating properties. Therefore,
it is a good habit to change the oil in ever machine every so many hours(
or miles, or revolutions... think of cars, lawnmowers, etc.) A
dessicant filter on the vacuum line would also help. Most dessicant
filters are made for air line applications ( positive pressure), not
vacuum lines (negative pressure). Therefore, I don't think Grainger has
them. Try an industrial rubber hose supplier in your area. The rubber
hose suppliers usually handle vacuum and hydraulic fittings and
accessories. Good luck and change that oil. ( No, I don't work for
Shell, BP, Exxon or any other oil giant!)
Bill Amsterlaw on mon 10 mar 97
Thanks for the information you posted to Clayart about my problem of getting
moisture in the pugmill vacuum pump oil.
I noticed the creamy layer on top of the oil when I changed it just a few
weeks ago and it developed again almost immediately.
I have managed to find a variety of units that claim to remove moisture. They
come in a wide variety of sizes and prices. Some contain a replaceable
cartridge that absorbs moisture and some just have a little filter that you
clean periodically. Most of these units are sold to be attached to air
compressors. Nobody I have communicated with seems to know exactly what size
and type unit would best suit my need. I found a unit at Wal-Mart for $20
that says it removes moisture that has a water trap and a little filter in it
that you can clean yourself. I finally did find some units in the Grainger
online catalog, one of which looks identical to the Wal-Mart unit - only it is
listed for $40 in the Grainger catalog.
Do you know the manufacturer and model of a desiccant unit that would do the
job? Should I be looking for something with replaceable cartridges? What
A desiccant filter on the vacuum line would also help. Most desiccant filters
are made for air line applications (positive pressure), not vacuum lines
(negative pressure). Therefore, I don't think Grainger has them. Try an
industrial rubber hose supplier in your area. The rubber hose suppliers
usually handle vacuum and hydraulic fittings and accessories.
- Bill Amsterlaw (email@example.com)