Page 3-6
Document Ref 942175-001 Rev 3
TQM Meter for Fuel Dispensers
Component Technical Manual
3.6
Flushing and Calibration Instructions (Non MID Dispensers)
Tokheim dispensers are accurately calibrated before leaving the factory using a test liquid
with viscosity and density properties between diesel and gasoline. Any meter error caused
by these viscosity and density differences is minimal, however during initial field calibration,
meter errors can go above the acceptable limits and would therefore require a meter
adjustment. These errors are more likely to be caused by another source such as insufficient
flushing of the hydraulic system and not by a wrong adjustment in the factory.
To prevent erroneous meter adjustments, the following flushing guidelines should be observed:
1)
Run each filling position of the dispenser until fuel comes out of the nozzle.
2)
It is recommended that pump and nozzle filter(s) are cleaned.
For submerged pumps, close the under pump safety valve before attempting to clean
the filter.
3)
Flush each dispenser filling position with 40 liters (e.g. 2 x 20 L cans) to remove any
construction and installation dirt and /or air.
(Point 1 must be carried out first then flush with the 2x20 liters cans).
The flushing process must be carried out at the maximum flow rate of each nozzle.
(36 LPM minimum. At lower flow-rates the evacuation of air in the hydraulic
system will take longer therefore the stability of measurements will take longer).
4)
Test each filling position of the dispenser. The calibration of the meter for the filling
position is completed when the result is within acceptable tolerance limits.
(Depending on the market, this could be either “strike” or below “strike” = less in the
can than on the display)
5)
If the calibration result is out of the tolerance limits, re-test until two consecutive
calibrations show similar results or the meter error is within the acceptable tolerance
limits. (See point 4)
6)
Adjust the meter when it is still out of the tolerance limits but showing similar results
after two consecutive calibrations.
7)
Re-test to confirm that the meter error is within the tolerance limit.
8)
If the meter error is still not within tolerance limits or stable after 4 consecutive
calibrations, either the installation or the meter can be the cause.
(Decision to replace taken after 40 L to flush and 80 L for the calibrations).
9)
Check the installation. If the meter on the opposite filling position with the same
product is OK then the fault is probably with the meter. Replace the meter if no
failures can be found on the installation.
