Issue Date: July 14, 2003
Dresser Wayne Europe
(Model 924, 2 inch dia Floats, Magnetostrictive Probe)
AUTOMATIC TANK GAUGING METHOD
||Leak rate of 0.2
gph with PD = 97.8% and PFA = 2.2% for 30 minute test.
Leak rate of 0.2 gph with PD = 99.4% and PFA = 0.6% for 1 hour test.
Leak rate of 0.2 gph with PD = 99.7% and PFA = 0.3% for 2 hour test.
Leak rate of 0.2 gph with PD = 99.9% and PFA = 0.1% for 3 hour test.
A tank system should not be declared tight if the test result indicates a
loss or gain that equals or exceeds this threshold.
||Maximum of 20,000
Tank must be minimum 50% full for 1 hour test.
Tank must be minimum 14% full for 30 minute, 2 hour and 3 hour test.
Minimum product level required based on 14% full tank and tank diameter is
48" dia/min 9.5";
120" dia/min 24.7".
For other tank diameters, consult manufacturer.
||Minimum of 8
hours between delivery and testing.
There must be no delivery during waiting time.
Minimum of 30 minutes between dispensing and testing.
Minimum of 30 minutes, 1, 2 or 3 hours.
Test data are acquired and recorded by system's computer.
Leak rate is calculated as the difference between the first and last data
There must be no dispensing or delivery during test.
product is determined by a probe containing 5 thermistors with the lowest
thermistor located at the 10% tank volume level above the bottom of the
||Must be used to
detect water ingress.
Minimum detectable water level in the tank is 0.75 inch.
Minimum detectable change in water level is 0.08 inch.
probe must be checked and, if necessary, calibrated in accordance with
using manifolded tank systems. Therefore, this certification is only
applicable when there is a probe used in each tank and the siphon is broken
Tests only portion of tank containing product.
As product level is lowered, leak rate in a leaking tank decreases (due to
lower head pressure).
Consistent testing at low levels could allow a leak to remain undetected.
EPA leak detection regulations require testing of the portion of the tank
system which routinely contains product.
Dresser Wayne AB
Ken Wilcox Associates
Limhamnsvagen 109, Box 30049
SE-200 61 Malmo, Sweden