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6) Inspection of the coupling spider
Check the spider of the coupling which connects the main pump unit and motor of the pump
for damage. If cracks or fractures are found on the spider, replace it in accordance with “
6.4
Replacement of the coupling spider
.”
7) Inspection of the oil mist separators
When using the oil mist separators in replacement of the standard outlet pipe, pay attention
to the clogging of the filter in the oil mist separators. If the clogging advances, evacuated gas
cannot be exhausted any longer, which causes the oil gauge to protrude and oil leakage from
the shaft seal section or drain plug seal section. The maximum internal pump pressure is
0.03 MPa (gauge pressure).
When the pump is operated continuously for a long time or when the pump is extremely
contaminated with evacuated gas, overhaul is required. Contact the nearest sales or service
department among those listed at the back of this manual.
When requesting the manufacturer’s service department to overhaul the pump,
always write the type of the vacuumed gas on the “Pump Usage Check Sheet”
attached at the back of this manual and submit it. Note that if toxic gases are
exhausted, both the pump itself and pump oil will become contaminated. Please
be sufficiently aware that use with some gases will preclude overhaul.
6.3 Replacement of the pump oil
The pressure of the vacuum device may increase due to the deterioration of the pump oil. In
such a case, close the inlet port of the pump and check that the specified ultimate pressure has
been reached. If not, replace the pump oil. If substances having a high vapor pressure (such as
moisture or solvents) are mixed with the pump oil, or if sludge is accumulated at the bottom of
the pump, the ultimate pressure cannot be reached with only one replacement and the pump oil
must be replaced several times. The deterioration of the pump oil is caused not only by the
contamination due to evacuated gas but also by the changes in the properties of the pump oil
itself (depending on the operation time). Periodic replacement in accordance with Table 4
showing an oil replacement guide is recommended.
Danger
