What Happens When Your CNG Tanks Expire?

Industry experts continue to explore options for possible CNG tank recertification, as well as safer tank disposal, a federal CNG vehicle registration system, and government grant help.

August 2013, - WebXclusive

by Cheryl Knight - Also by this author

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"If we keep them beyond the cylinder's service life, we will buy replacement tanks and install them," said Battersby. "One reason for considering keeping them is that we don't have a competitively priced option to buy another CNG vehicle. The manufacturers stopped making them in the late '90s, and our only option is an aftermarket retro kit, which can double the cost of the new vehicle."

Battersby believes the demand is there to support additional OEM offerings in CNG light-duty trucks and vans, but is frustrated the industry is not seeing them brought to the U.S. market ... yet.

However, General Motors Co. and Ford have hinted at plans to offer CNG-ready vehicles in the near future. Industry sources expect GM will once again offer a gaseous fuel-prepped engine for its full-sized CNG van, pickup, and chassis cab models in about two years, and Ford, which already offers two gaseous fuel-prepped engines for its full-sized pickups, vans, and cutaways, may add the option to additional models.

The University prefers not disposing an NGV vehicle without buying an NGV replacement, not only because of environmental benefits, but also because customers are conditioned to the NGV vehicle.

Battersby and his staff will also soon  explore a drop-in electric-vehicle conversion, called ElectraDrive in a low mileage, of formerly CNG-powered chassis. The California-based ElectraDrive company offers to repower existing truck/van chassis with a complete electric-vehicle drivetrain. The County of Alameda General Services Administration is conducting a pilot project with the ElectraDrive conversion.

"We dispose of our CNG vehicles the same way as we do our regular vehicles, through the State of California auction site. Plus, we have a property disposal unit on campus, and they sell campus vehicles on occasion," Battersby said. "We are considering selling some of our equipment using an online service called Public"

Develop Options for CNG Tank Expiration in Advance

Battersby has found while guidance is given about tank safety and expiration, noncompliance is not subject to regulatory punishment.

"There is no 'enforcement' of these rules, but if you continue to use a tank that is past its expiration, then the liability is all on you. The tank manufacturer, tank installer, and the tank inspector are all cleared of any liability," he stated.

Expiration dates for all CNG fuel tanks are displayed on labels located on the tanks, as well as on warning labels in the engine compartment. 
"The tank should be destroyed upon its expiration because there is no re-hydrotesting of CNG tanks and returning them back into service," Battersby said. "Have a qualified technician replace the fuel tank. Do not reuse the old fuel tank!"

He emphasized the importance of being aware of each individual vehicle's CNG tank expiration so a plan can be implemented before the expiration date. For instance, when the tanks near expiration, will the vehicle be retained? If so, have re-tanking options, costs, and ­benefits been researched?

"Keeping these vehicles in service could mean avoiding a big expenditure, as well as not losing out on the environmental benefits associated with them," Battersby added.

He also pointed out that because some CNG vehicles have specific tank size limitations, managers should make sure if they replace the tank, the new tank purchase is compatible with the vehicle.

"Also, make sure if you purchase a replacement tank that it has not been sitting on the shelf for five years. If it has, it's already lost five years of its lifecycle," he said.

The University is considering applying for grant applications to re-tank its existing NGVs. "This way, we wouldn't lose some of our throughput," Battersby added.

According to Lucintel, a leading global management consulting and market research firm, the CNG tank market witnessed double-digit growth during the last decade and is expected to grow at a similar rate for the next five years (2010-15). Lucintel also said the global composite CNG tank market for the automotive industry is forecast to reach $368.8 million by 2015.

Will the market keep up with demand, as well as implement new tank safety standards, tracking systems, and disposal methods? With people such as Yborra and Battersby furthering the discussion about CNG practices and roadblocks, progress may indeed be made.

From HDT's sister publication, Government Fleet.

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  1. 1. Gordon Botts [ August 25, 2013 @ 04:46AM ]

    This a great article about a subject that all of us in the repair industry are not well informed about.

  2. 2. Jay Duca [ September 04, 2013 @ 07:59AM ]

    In the article it states “a variety of community colleges and other organizations provide training”. Is there a source for this training that you are aware of and is the training certified by the NHTSA? If there is a source for the training could you please list it for me?

    Thank you
    Jay Duca

  3. 3. Wilfredo Rivas [ April 21, 2015 @ 04:47PM ]

    I bought a 2012 Honda Civic in August 2013. Where can I bring the car so I can see if the gas tank has the correct amount of pressure to contain the natural gas that powers it?
    I live in Los Angeles in California by the way.

  4. 4. william sadler [ August 11, 2015 @ 12:57PM ]

    All this is B/S with the org. question. what to do with old tanks , expired tanks. You have not answered the question. If you auction them off you are giving someone else the problem with bad tanks. Who do you dispose the tanks to, THAT IS THE QUESTION.

  5. 5. Destiny [ January 22, 2018 @ 10:09AM ]

    We are in the forklift industry. I have came across an older CNG tank that I would like to get rid of. How would I go about doing that and what is the best route to take?


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