
UNIBLOC-PD Operation & Service Manual: PD600-677 11
Recommended Flush System Arrangement: PD602, PD652 & PD677
3.3.2 Double O-Ring & O-Lip Seal Flushing/Cooling
Double o-ring shaft seals, like the double mechanical seals, must also be fitted with flushing systems that will cool
and lubricate them, otherwise the seals will NOT OPERATE CORRECTLY. The flushing system may be arranged the
same as the double mechanical seals, shown in figures 3.4-3.6. The double o-ring seals may also be lubricated with
grease if the pump application justifies doing so. In this case, the seal flush chambers are filled through grease nip
-
ples with approved grease that is suitable for use with the pumped media.
Unibloc recommends using Lubriplate
Synxtreme FG-2 calcium sulfonate complex grease.
The chambers must be filled completely for proper operation.
This can be accomplished by over pressurizing the chambers such that grease will be squeezed out of the seals
along the shafts and into the rotor housing.
3.4 Pre-Start Check List
o
Check the pipes to make sure they have been purged of debris. Any remaining particles larger than 0.002 in.
(0.05 mm) can damage the pump if they enter it. A filtering device installed before the pump inlet is highly
recommended to insure safe and proper operation. Since such a device will restrict the flow to the pump, it is
necessary to verify that the net positive suction head (NPSH) available is not reduced below that required by
the pump.
Unibloc-Pump stocks in-line strainers which will prevent hazardous objects from entering
the pump and will capture them for easy removal from the system.
o
Check all obstructions to make sure they have been removed from pipe or pump.
o
Check pump connections and make sure they are tight.
o
Check lubricant levels to make sure they are correct.
o
Check that safety guards are in place.
o
Check inlet and outlet valve to make sure they are open and functional.
o
Check the seal flushing is connected and activated, if applicable.
HORIZONTAL PUMP PORTS
VERTICAL PUMP PORTS
CONTROL VALVE
(i.e. diaphram valve)
PRESSURE
GAUGE
CHECK
VALVE
CHECK
VALVE
FLUSH
INLET
FLUSH
OUTLET
FLUSH
INLET
SHUT OFF
VALVE
SHUT OFF
VALVE
CONTROL VALVE
(i.e. diaphram valve)
PRESSURE
GAUGE
CHECK
VALVE
FLUSH
INLET
FLUSH
OUTLET
SHUT OFF
VALVE
fig. 3.6