Navigation Links
NIST corrosion lab tests suggest need for underground gas tank retrofits
Date:7/31/2014

A hidden hazard lurks beneath many of the roughly 156,000 gas stations across the United States.

The hazard is corrosion in parts of underground gas storage tankscorrosion that could result in failures, leaks and contamination of groundwater, a source of drinking water. In recent years, field inspectors in nine states have reported many rapidly corroding gas storage tank components such as sump pumps. These incidents are generally associated with use of gasoline-ethanol blends and the presence of bacteria, Acetobacter aceti, which convert ethanol to acetic acid, a component of vinegar.

Following up on the inspectors' findings, a National Institute of Standards and Technology (NIST) laboratory study* has demonstrated severe corrosionrapidly eating through 1 millimeter of wall thickness per yearon steel alloy samples exposed to ethanol and acetic acid vapors. Based on this finding, NIST researchers suggest gas stations may need to replace submersible pump casings, typically made of steel or cast iron, sooner than expected. Such retrofits could cost an estimated $1,500 to $2,500 each, and there are more than 500,000 underground gas storage tanks around the country.

The NIST study focused only on sump pump components, located directly below access covers at filling stations, just above and connected to underground gas storage tanks. The sump pumps move fuel from underground tanks to the fuel dispensers that pump gas into cars. These underground tanks and pipes also may be made of steel and could be vulnerable, too. "We know there are corrosion issues associated with the inside of some tanks. We're not sure, at this point, if that type of corrosion is caused by the bacteria," NIST co-author Jeffrey Sowards says.

Much of the U.S. fuel infrastructure was designed for unblended gasoline. Ethanol, an alcohol that can be made from corn, is now widely used as a gasoline additive due to its oxygen content and octane rating, or antiknock index. A previous NIST study found that ethanol-loving bacteria accelerated pipeline cracking.**

For the latest study, NIST researchers developed new test methods and equipment to study copper and steel alloy samples either immersed in ethanol-water solutions inoculated with bacteria, or exposed to the vapors above the mediumconditions mimicking those around sump pumps. Corrosion rates were measured over about 30 days.

The NIST study confirmed damage similar to that seen on sump pumps by field inspectors. The worst damage, with flaky iron oxide products covering corrosion, was found on steel exposed to the vapors. Copper in both the liquid and vapor environments also sustained damage, but corrosion rates were slower. Steel corroded very slowly while immersed in the liquid mixture; the NIST paper suggests bacteria may have created a biofilm that was protective in this case.

Although copper corroded slowlyit would take about 15 years for 1.2-millimeter-thick copper tube walls to develop holeslocalized corrosion was observed on cold-worked copper, the material used in sump pump tubing, NIST co-author Elisabeth Mansfield notes. Therefore, stress-corrosion cracking is a concern for bent copper tubing because it would greatly reduce tube lifetime and result in leaks.

The NIST test equipment developed for the study could be used in future investigations of special coatings and biocides or other ways to prevent sump pump failures and leaks.


'/>"/>

Contact: Laura Ost
laura.ost@nist.gov
National Institute of Standards and Technology (NIST)
Source:Eurekalert  

Related biology news :

1. UC research tests new tool to guide reintroduction of the American chestnut
2. VolitionRX Raises Over $1 Million To Begin Clinical Trials of Blood Based Diagnostic Tests
3. Dip chip technology tests toxicity on the go
4. Lab tests show arthritis drug effective against global parasite
5. Nanotechnology breakthrough could dramatically improve medical tests
6. Report addresses challenges in implementing new diagnostic tests where they are needed most
7. UF researcher tests powerful new tool to advance ecology, conservation
8. Clinical trial tests rice bran to prevent cancer
9. Game changing diagnostic & prognostic prostate cancer genetic tests revealed by Jefferson
10. Rapid, point-of-care tests for syphilis: The future of diagnosis
11. First tests of old patent medicine remedies from a museum collection
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
NIST corrosion lab tests suggest need for underground gas tank retrofits
(Date:3/10/2016)... --  Unisys Corporation (NYSE: UIS ) today announced ... testing its biometric identity solution at the Otay Mesa border ... identify certain non-U.S. citizens leaving the country. ... determine the efficiency and accuracy of using biometric technologies in ... until May 2016. --> the United States ...
(Date:3/3/2016)... , March 3, 2016  FlexTech, a SEMI Strategic ... of Innovation, Research & Development, Leadership in Education, and, ... is the 9 th year of the FLEXI ... companies and individuals from past years . Judging ... a pre-described set of criteria, by a panel of ...
(Date:3/1/2016)... , March 1, 2016 /PRNewswire/ ... announced the addition of the  "Global ...  report to their offering. ... the addition of the  "Global Biometric ...  report to their offering. --> ...
Breaking Biology News(10 mins):
(Date:4/29/2016)... ... April 29, 2016 , ... Proove Biosciences, Inc ., ... the launch of the Proove Health Foundation . The Foundation is a ... the use of personalized medicine for tackling the nation’s most-pressing healthcare epidemics. As ...
(Date:4/29/2016)... ... ... Intelligent Implant Systems announced today that the two-level components for the Revolution™ Spinal ... These components expand the capabilities of the system and allow Revolution™ to be ... 2015, the company has seen significant sales growth in 1Q 2016, and the system ...
(Date:4/28/2016)... ... 28, 2016 , ... Next week on May 5 at ... technologies for tissue stem cell counting and expansion to gene-editing scientists and other ... CRISPR-based Genome Engineering in Burlington, Massachusetts. , The attention of most gene-editing scientists ...
(Date:4/27/2016)... , ... April 27, 2016 , ... The Pittcon Organizing ... 2019. Chuck has been a volunteer member of Committee since 1987. Since then, ... board of directors and treasurer and was chairman for both the program and exposition ...
Breaking Biology Technology: