Specifications

5
Installation
Pumps should be carefully unpacked
and checked to make sure that the ship-
ment is complete. If any items are miss-
ing or damaged, the freight carrier and
Zenith
®
should be notified immediately.
The following is a general installation
procedure. For special applications,
considerations, or simply to ask for
advice, please contact our Applications
Engineering Group.
It is not recommended to flush
downstream process equipment utilizing
Zenith
®
precision metering pumps. Most
fluids used as flushing agents, such as
solvents and water, have a low viscosity
and have poor lubricating qualities.
Catastrophic failure may occur
under certain operating conditions. If it
is necessary to flush the system, the
following suggestions are recommended
to prevent premature pump failure:
1) If possible, flush the system using a
lubricating fluid.
2) Minimize the differential pressure
across the pump ports to 25 psi.
3) Reduce the pump speed to an
acceptable level (approximately 10
rpm).
4) Flush the pump for the shortest
allowable time, yielding effective
cleansing of the system, and no
longer than necessary.
5) It is recommended to use a bypass
around the pump as illustrated in
Figure A. This will allow for high velocity
flushing of the system while minimizing
risk to the metering pump. During the
flush cycle, fluid will pass through and
around the pump. This will allow the
system to be flushed quickly and
effectively.
To prepare the pump for use:
1) Always flush out the plumbing system
before connecting the pump.
2) Filters should be installed prior to the
pump inlet and should filter ideally to
half the pump gear clearances.
3) Turn pumps by hand before running.
Pumps should turn freely.
4) Pivot mount pumps should be mounted
in the L-5677 mounting saddle, and
the trunnions should be loosely
tightened to support but not restrict
movement of the pump. Fixed-mount
pumps should be installed on an
L-shaped saddle, and mounting
screws securely tightened.
5) Make certain that bearing grease has
been applied between the hub and
Outer Drive Gear. If necessary, apply
a suitable lubricant to the grease fitting
located on the pump. Rotate the Outer
Drive Gear, by hand, to ensure that a
layer of grease is evenly spread
between the hub and outer drive gear
bearing area. Pumps without a grease
fitting do not require lubrication.
Note: Lubrication applied to a grease
fitting will not lubricate internal bearings
or come in contact with the pumped fluid.
6) Carefully mesh the outer drive gear
with the drive pinion gear. A backlash
of .005" is recommended. Trunnions
can then be securely tightened.
7) Make sure the pump is primed before
starting. Be sure to apply positive inlet
pressure when metering high-viscosity
fluids. Pumps with universal face seals
require approximately 25-50 psi inlet
pressure to seat the seal.
8) Start the pump slowly and, if possible,
operate with a lubricating fluid.
9) When satisfactory operation is
achieved, the pump and system may
be gradually brought up to normal
operating conditions.
10) If, at any time during operation, the
pump does not appear to be running
smoothly, stop the pump immediately
to avoid serious internal damage.
Pump
Valve
Bypass
Figure A