Issue Date: March 27, 2018

Leighton O’Brien

Dry Test (Pressure Decay Test)

NON-VOLUMETRIC TANK TIGNTNESS TEST METHOD (ULLAGE)

Certification

Leak rate of 0.1 gph with PD = 100% and PFA = 0%.

Leak Threshold

A tank system should not be declared tight when the pressure decay trend results in an indication of failure or inconclusive on the test apparatus screen.

Applicability

Gasoline, diesel, aviation fuel, fuel oil #4, biodiesel blends B6-B20 meeting ASTM D7467, biodiesel B100 meeting ASTM D6751. 

Tank Capacity

Maximum tank volume evaluated is 20,000 gallons. Larger tanks may be tested provided that the Test Period is correspondingly increased by extrapolation.

Waiting Time

Not evaluated.

Test Period

Average is 15 minutes with tank filled to 5%
Average is 6 minutes with tank filled to 50%
Average is 3 minutes with tank filled to 95%
There must be no dispensing or delivery during test.

Test Pressure

Proprietary.

Temperature

Not evaluated.

Groundwater

Depth to groundwater in tank excavation backfill must be determined.
If groundwater is above product level, net test pressure must be increased by 2.2 psi (15 kPa) in the ullage during the test.

Comments

Not evaluated using manifolded tank systems.
Evaluated using unleaded fuel calibrated orifice.
Tests only ullage portion of tank.
Product-filled portion of tank must be tested using a volumetric underfill test method.

 

 

Leighton O’Brien

Evaluator:  Ken Wilcox Associates

3rd Floor, 20 Council Street

Tel:  (816) 443-2494

Hawthorn East, Victoria, Australia 3123

Dates of Evaluation: 12/01/2016

Tel: +61 3 9804 220

 

E-mail: info@leightonobrien.com

 

URL: www.leightonobrien.com

 

 

 | Home | Vendors: A - F | Vendors: G - M | Vendors: N - S | Vendors: T - Z | Method Index | Glossary |

Appearance on this list is not to be construed as an endorsement by any regulatory agency nor is it any guarantee of the performance of the method or equipment.
Equipment should be installed and operated in accordance with all applicable laws and regulations.  For full details, please refer to our expanded "DISCLAIMER" page.