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4
DEFINING
| WHAT’S NEXT
214916 revision A
September 2019
OTHER TEST(S)
•
Perform other test(s) as required by authorities having
jurisdiction.
WARNING
Replace the nozzle if the nozzle fails any of the
above tests. Failure to comply could result in
property damage, injury or death.
See OPW’s website at www.opwglobal.com or contact an
OPW Distributor for troubleshooting guides and/or how to
use the OPW nozzle.
A/L TESTING WITH A GAS FLOW METER
(WET TEST):
1. Vent the UST system to atmosphere before starting the
A/L Testing procedure.
2. You will need to purchase/obtain an A/L Test Adaptor.
3. Securely attach the tubing from the gas flow meter to the
hose-barb fitting on the A/L Test Adaptor.
4. Slide the A/L Test Adaptor over the nozzle spout so that
the adaptor covers the vapor return path.
5. Initialize the gas flow meter to begin to measure the
volume of vapor collected.
6. The dispenser must be turned on and authorized to be
able to open the nozzle and dispense fuel.
WARNING
Static electric spark could ignite fuel, causing a
fire. Place a container approved for fuel on the
ground prior to and during test. Nozzle must be in
contact with the container until the testing is
complete to discharge any static generated
during the test.
7. Dispense approximately 20 litres of fuel into an
approved test container with the nozzle lever held in the
full open position.
8. Calculate A/L ratio by dividing the volume of vapour
collected by the volume of fuel dispensed.
9. If the A/L ratio is between the desired range, then no
further adjustments are necessary.
10. If the A/L ratio is outside the desired range, then follow
the vacuum system manufacturer’s instructions for
adjusting vapour flow rates. Retest and verify that
adjustments now bring the A/L ratio into compliance.
11. Reseal the UST vapour system after the A/L ratios are
set for all fueling points.
Correction Factor ‘K’:
As ambient air is sucked in during the wet test, the
calculated air volumetric flow must be divided by the
correction factor. If this is not already done automatically by
the handheld control, the vapor recovery rate is calculated
using one of the following equations:
(1)
𝑹𝑹
=
𝑽𝑽
𝒂𝒂
𝑽𝑽
𝑲𝑲
∙𝑲𝑲
∙ 𝟏𝟏𝟏𝟏𝟏𝟏
(2)
𝑹𝑹
=
𝑽𝑽
𝒂𝒂
𝑽𝑽
𝑲𝑲
∙𝑲𝑲
∙
𝒕𝒕
𝟔𝟔𝟏𝟏
∙ 𝟏𝟏𝟏𝟏𝟏𝟏
For further details, please refer to prEN 16321-2
R
Vapor recovery rate, in %
V
a
Measured air volume in litres
V
k
Simulated petrol volume in litres
Q
a
Measured air volume flow rate in L/min
(mean value)
K
Correction factor
(as specified in the certificate)
t
Measuring time in seconds
