8
190-999 Rev G
MT8 Installation (Cont’d)
Initial Start-Up Procedure
Before you start the pump, be sure that:
1. All shut-off valves are open, and pump has adequate supply
of fluid.
2. All connections are tight.
3. The oil level is 1 in. (25 mm) from the top of the crankcase.
4. Open priming valve on system back pressure valve so
pump starts under minimum pressure. See Typical Metering
Installation drawing.
5. Be sure unused manifold ports are properly plugged.
Refer to
page 20
for appropriate plug kit.
Turn on power to pump motor and:
1. Check inlet pressure. To maintain maximum flow, pump inlet
should be under flooded suction conditions at all times. Inlet
pressure must not exceed 250 psi (17.3 bar).
2. Observe any erratic noise or flow.
3. Jog pump on and off until fluid coming from priming valve is
air-free.
4. Close priming valve.
5. Perform pump calibration. See Calibration Procedure.
Calibration
Note: Each metering pump or pump system must be
calibrated to determine the pump speed required for the
desired flow rate.
Accurate calibration depends on pump discharge pressure and
system conditions. When calibrating the pump or system, it is
useful to plot capacity curves for future reference. Observe on
the curve, that pump capacity decreases slightly as discharge
pressure increases.
In order to achieve the best possible results, perform calibration
under actual process conditions. Follow these steps:
1. Run pump for 20 minutes at actual process conditions. If
process system cannot be used, circulate back to supply
tank through pressure relief valve (see Typical Metering
Installation drawing). If required system pressure is less than
50 psi (3.5 bar), a back pressure valve must be installed and
set to produce minimum of 50 psi (3.5 bar) pressure at pump
head.
2. Determine maximum pump speed required for all system
conditions that need to be satisfied. Measure pump delivery
at this maximum speed using system calibration cylinder,
flow meter, or similar container. This is the “rated capacity”
for pump.
3. Measure pump delivery at 100%, 75%, 50%, 25%, and
10% of maximum speed just determined. Let pump run for
5 minutes at each speed setting or manual adjust setting
before taking capacity measurement.
Tips for Priming
Do not inspect the diaphrams
This is often the first impulse, but it should only be the last
resort. Disassembling the pump to inspect the diaphragms
will cause a loss of prime in the hydraulic (power) end. A
diaphragm repair kit will then be needed to replace the PTFE
components.
Increase motor speed
Gearboxes with a ratio of 30:1 or higher tend to have more
priming issues. In such cases, “overspeed” the motor–
starting at 200 revolutions per minute (rpm) or more–so that
the pump speed is approximately 150 revolutions per minute
(rpm).
Alternatives to increasing motor speed
1. Start and stop the pump.
2. While the pump is running, remove the main pressure
relief valve (PRV) to see if any air became entrapped in the
hydraulic end during shipping.
3. Temporarily install a priming pump to feed the MT8 until it
primes.
Different check valve materials
Wanner Engineering has determined that the inability to prime
is because the PTFE O-rings inside the check valve are not
sealing.
Contact factory for internal check valve O-rings in another
material:
FKM (Viton®) – We will supply test check valves with FKM
O-rings at no cost.
FFKM (Kalrez®) – We consider FFKM O-rings a good
option for high gearbox ratios. Due to the expense of FFKM,
however, there will be a cost.
Checklist of other solutions
• Do not try to prime against system pressure.
• Do not open any bypass valves.
• Make sure that the inlet conditions are proper, including
NPSH.
• If priming outdoors, the pump temperature must be above
40 ̊F (4.4 ̊C)
• Verify that the pump shaft is turning by removing the oil cap
to view the crankshaft.
• The main PRV must be in place, or no fluid will pump.
• If it sounds like the gearbox is making a knocking sound, and
the flow rate is low, then air is entrapped in the fluid end of
the pump. (It is not the gearbox regardless of the sound.)
