Universal Pump Service Manual
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Testing Flow Range Compensation
The Calibration Sheet Addenda in this manual can be used to document this testing.
Compensation is factory preset. SKC recommends that compensation be checked periodically during routine maintenance to
assure pump accuracy. Flow compensation will need to be reset if non-factory repairs have been made (see Pump Reassembly,
Se ing Flow Compensation). Do not perform a compensation check unless the ba ery voltage is at least 6.1 volts.
When checking battery voltage, ensure tester probes are oriented properly to avoid short-circuiting
the battery.
Universal XR Sample Pumps should be able to maintain fl ow at:
1000 to 2500 ml/min at 40 inches water back pressure
3000 ml/min up to 35 inches water back pressure
4000 ml/min up to 20 inches water back pressure
5000 ml/min up to 10 inches water back pressure
Tools
• Universal XR Series pump (fully assembled)
•
Dual-ball rotameter,
valve,
magnehelic gauge
• Small fl at-head screwdriver
connected with tubing in line and in order
• Calibration Sheet
1. Turn on the pump.
2. With the pump inlet a" ached to the magnehelic gauge outlet and at minimum back pressure, adjust the fl ow
adjust pot on the front of the pump until the dual-ball rotameter reads 1000 ml/min.
3. Slowly increase back pressure up to 40 inches. The dual-ball rotameter should remain stable at 1000 ml/min. If
the balls deviate by more than ± 5% during the back pressure increase, it is out of tolerance (
see Pump Reassembly,
Se ing Flow Compensation
).
4. Release back pressure and repeat Steps 2 and 3 at 3000 ml/min and 35 inches water back pressure. If the reading
stays within ± 5% at both 1000 ml/min and 3000 ml/min, the pump should be “in spec” at any other fl ow point. If
readings deviate by more than ± 5%,
see Pump Reassembly, Se ing Flow Compensation
.
Testing the Pressure Regulator
This is only required if the low flow mode is used frequently. Check the pressure regulator periodically during
routine maintenance to assure pump accuracy. The pressure regulator is factory preset to 20 inches water back pressure at
1500 ml/min. It will need to be reset if non-factory repairs have been made (see Pump Disassembly, Se ing the Regulator).
Tools
• Universal XR Series pump (fully assembled)
•
Dual-ball rotameter,
valve,
magnehelic gauge
• Small fl at-head screwdriver
connected with tubing in line and in order
1. Remove the two cap screws from the top of the pump (Figure 1, #15 and 16) and turn on the pump.
2. Place the pump in the low fl ow mode by turning the smaller screw counterclockwise (Figure 1, #16). This is the
regulator shut-off screw. Turning this screw counterclockwise opens the regulator isolation valve allowing air to
enter the regulator. This screw should be turned four full turns to be sure the valve is fully open.
3. With the pump inlet a" ached to the magnehelic gauge outlet and at minimum back pressure, set pump fl ow to
1500 ml/min. Turn the fl ow adjust pot on the pump until the dual-ball rotameter reads 1500 ml.
4. Close off the inlet to the dual-ball rotameter.
5. Observe the magnehelic gauge. It should indicate 20 inches water back pressure (± 1 inch). If it does not,
see Pump
Disassembly, Se ing the Regulator.
If pump passes all functional testing successfully, no further service is required.
