16
Operation and Maintenance Manual
QC Series Centrifugal Pump
QC-M02
IMPORTANT:
When you mount the backplate onto the adapter, the seal may supply resistance.
If this resistance is too much, check the seal assembly and be sure the drive tcollar has been
located correctly. The efficiency of the “E” seal relies on the proper installation of the drive collar.
The space in the stuffing box should contain both carbons in a balanced state of pressures and
distances.
Figure I.
The next step is to close the stuffing box. To do this, you need to pull the follower against the
backplate. Use the machine screws (
17A
) and lock washers (
17C
) to close it, tightening until the
lock washers are flattened. The screws on a circular arrangement can be tighten across and
varying positions when screwing.
It is recommended to set the backplate so that the 1/8 NPT drill-holes on the stuffing box, point
upward and with a 45º inclination from the horizontal
plane, as shown in
Figure J.
The water should enter through one connection and
leave through another, moving through the stuffing box
and in the process, cooling it.
The ideal quantity of water will depend upon
the temperature of your application. For vacuum
applications it is recommended to use a flow of 10
drops per minute, while maintaining a temperature of
176º F inside the seal around 3 gallons per hour are
required.
IMPORTANT:
When servicing pumps with “D”, ”DG”,
”F”, or “E” seals, inspect all disposable parts such
as: carbon seals (be sure they have no bumps or
scratches), o-rings (they should maintain a circular form
and should not be bitten). In the case of abrasive fluids, use EPDM material for all gaskets and
o-rings. When dealing with high temperatures, use Viton.
Springs are not subject to wear because of tension or compression, except in extreme cases.
Carbon seals made of silicone, tungsten or ceramic are very fragile but resist abrasive and
corrosive fluids.
45º
ASSEMBL
Y
