VaporTEK System Description
VaporTEK Pump
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MDE-5394B VaporTEK™/VaporTEK-3 Controller Board 110 V UL® Vapor Recovery Collection System for Encore® 500 S
Start-Up and Service Manual · March 2019
System Calibration
VaporTEK more precisely controls the amount of vapor being collected so that it is closer to
the fuel delivered. It drives the pump at the speed required to deliver the same vapor flow as
the fuel. A typical relationship between pump flow and speed at 150 mbar inlet suction
pressure and 100 mbar discharge pressure at 2500 rpm is shown in
.
Figure 3-3: Relationship Between Pump Flow and Speed
By characterizing the relationship between the pump speed and vapor flow during system
setup, or calibration, and then controlling the speed of the pump during operation as dictated
by the resulting curve of flow vs. speed, you can maintain the proper A/L Ratio better than by
relying solely on the vapor valve in the nozzle.
The Pump Control Node (PCN) in the dispenser outputs pulses proportional to the flow:
136 pulses = 1 LPM. These pulses are delivered to the Point of Sale (POS) system and the
dispenser display, and determine how much to charge the customer for the fuel dispensed.
These pulses are used by the VaporTEK system to set the vapor flow.
During the calibration process, the VaporTEK Controller Board drives the pump at a series of
15 speed settings between 1200 rpm and 0 rpm from each side separately. From this set of
data, it develops a curve that it will use to drive the pump during dispensing.
For example, during the calibration procedure, the pump speed required to deliver
30 LPM is 750 rpm and to deliver 40 LPM it is 1000 rpm. During operation, if the dispenser
pumps 35 LPM of fuel, the VaporTEK Controller will drive the pump at approximately 875
rpm to match this flow. Because the computer develops a smooth curve for the vapor flow
across the entire operating range of the pump, it can derive a speed setting for any level of fuel
flow between zero and the maximum of the dispenser.
150 mbar inlet suction and 100 mbar discharge pressure at 2500 rpm.
