Contaminated Air Stream
When the air stream contains a solid and/or liquid that
can contaminate the oil, it must be changed more often.
If the air stream contains a small percentage of contam-
inates and/or they are slightly aggressive* (mild acids,
etc.), synthetic oil, such as Busch R570, will resist break-
down better than the standard Busch R530. The solution
is to install a filter or knock-out pot to keep the contami-
nates out of the pump.
*Process air streams with a large percentage of contaminates and/or
more than slightly aggressive contaminates must use a once-through-
sealant or dry-type pump.
Oil change intervals can only be established by experi-
ence with the pump operating in the actual conditions
(see previous paragraph for some of the conditions).
Develop the oil change interval by periodically checking
an oil sample removed from the pump. When the oil
sample has become dark in color (from solids and car-
bonized particles) or is milky looking (from solids), it is
time to discard it. As mentioned before, a thorough flush-
ing may be needed.
3.2 Automotive-Type Oil Filter
The 0160 - 0630 Series, Single Stage, Rotary Vacuum
Pumps are equipped with an automotive-type oil filter
(Ref. 100). The 1000/1600 Series has two automotive-
type filters. The 0010 thru 0021 are not equipped with an
automotive-type oil filter. When replacing the automo-
tive-type oil filter, use only a genuine Busch filter.
Note:
Make sure to tighten the Busch oil filter securely
against the aluminum sealing surface so that leaks will
not occur.
3.3 Exhaust Filter
Every nine (9) to twelve (12) months, or as necessary,
replace the exhaust filter elements. The service life of
the exhaust filters varies widely with pump application. It
is only necessary to change the filters when the elements
become clogged with foreign material or burned oil.
Indications of clogged filters are smoke and oil mist com-
ing from the pump exhaust, higher than normal motor
current or oil leaking from the gas ballast valve on RA
models.
A pressure gauge (Ref. 90) is now supplied with your R5
vacuum pump as part of the oil fill plug. This gauge has
a green field and a red field. A pressure within the green
field would indicate normal pressure. Any pressure in
the red field (for a continuos period of time) requires an
immediate change of the exhaust filter(s).
In order to replace the filter, remove the screws retaining
the exhaust port cover plate. Pull the housing off the
exhaust box and set it aside. Use a slotted head screw
driver to loosen the exhaust filter retaining spring (Ref.
125), then rotate and remove the spring (see Fig. 3). Pull
the filter cartridge (Ref. 120) out of the exhaust box.
To field test an exhaust filter element, remove it from the
pump, allow it to cool, clean the sealing end (or O-ring
end), and use compressed air to blow through the ele-
ment. Apply approximately 3 to 6 psi, which is the max-
imum allowable operating pressure across the filter.
Note:
Use a shop rag to seal off the connection between
the air hose and the filter.
If you can blow through it, the
element is good. If not, discard it and install a new one.
The filter cannot be cleaned successfully. Visually
inspect the filter element for cracks.
Reinstall the filter elements. Make sure the open end of
the element is properly seated down in its recess in the
exhaust box with the O-ring (Ref. 121) correctly posi-
tioned. Retain the filter with the spring clip, tighten the
tension screw until the filter is secure. Place the exhaust
port gasket and cover in position on the exhaust box and
retain with the cap screws.
3.4 Vacuum Inlet Filter
If the pump is equipped with a special vacuum inlet filter
in applications where powder, dust or grit is present, the
filter cartridge should be cleaned on a weekly basis, or as
required, depending on the amount of foreign particles to
which the pump is exposed.
WARNING: If the gas entering this pump is a health
hazard, use rubber gloves and all necessary per-
sonal protection equipment when performing the
exhaust filter replacement operation.
WARNING: Wear safety glasses when installing or
removing the spring retainers. The retainers can, if
not secured correctly, slip off and fly out of the
exhaust box.
Fig. 3 - Removing Filter Spring
WARNING: Do not inhale through the filter or allow
your mouth to come in direct contact with the filter.
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