CNG tanks never expire?

[gringostar]

Here is another guy on ebay, says tanks never expire. He's selling a 2001 GX

From his ebay ad:

"Each CNG tank has the expiration date stamped on it. for my car the factory installed tank expires in 2015 and the extended tank that I installed expires in 2016. You are required to have the tank inspected at the expiration date of them but that does not mean at all that the tanks are not usable nor that they have to be replaced. A trained technician has to visually inspect the tanks for signs of deteroriation and stress if any, and all he or she can do is to give you a notice of his/her inspection. there is no law that reuqiures you to replace them. If the tanks are in good shape then there is noting to do and you can continue to use them"

http://cgi.ebay.com/ebaymotors/ws/eB...14#description

[John Mitton]

Re: CNG tanks never expire?

Wrong
There certainly is an expiration date on his Civic tank. As for weight of law, it is based on Dept of Transporation, Federal Motor Vehicle Safety Standard 304 regulations (this is also on his tank label).

[cowboy]

Re: CNG tanks never expire?

now that is something to be feared of

[cripple_rooster]

Re: CNG tanks never expire?

CNG tanks do expire. Newer ones can have an extended useful life due to more advanced production technics.

[gap23]

Re: CNG tanks never expire?

Has anyone had a tank they were told they had to replace ? just curious.

[Highmarker]

Re: CNG tanks never expire?

Has anyone had a tank they were told they had to replace ? just curious.

I inspected a 1997 Ford Contour last week and the tank expires the end of November this year. I informed the owner of the vehicle.

I also inspected a 1999 Ford van that had a tank with severe damage and informed him he had to remove the tank from service.

[cowboy]

Re: CNG tanks never expire?

bet you had a unhappy owner

[clnbrnr1]

Re: CNG tanks never expire?

I see so many tanks for sale on ebay, and it kills me to see them laying on the ground, in dirt ,on gravel and asphalt. Who would pay $1,000.00 or more for something being mishandled not to mention proper shipping methods?

[Highmarker]

Re: CNG tanks never expire?

bet you had a unhappy owner

cowboy,

Actually he wasn't unhappy. Most people put safety first.

[cowboy]

Re: CNG tanks never expire?

this is true but most of the time they bought the car to save money and have no clue when the cost gos through the roof, and the sad part is it mostly happens to nice folks who cant afford it and that is why they were trying to save money now there are some who can and just think its funny but most of the time when I am the bearer of bad news its those who can least afford it

[Highmarker]

Re: CNG tanks never expire?

Right you are Cowboy. Everybody in Utah is just trying to save a buck on fuel. The majority of the NGV owners don't even have the "Single Occupant HOV Lane Access". So, when you tell someone that their tank is expired or about to expire, or you tell them that their tank is damaged beyond repair and needs to be removed, you never know how they are going to react because it is a direct effect on their pocketbook. Luckily for the guy who owned the van, he had two other tanks on the van that were in good condition and can still drive the van once the damaged tank was removed.

People just need to do more research when purchasing a CNG vehicle. These are different vehicles than "gasoline" vehicles. You need to make sure the CNG system (tank is the main thing) is in good working order - tank is current on inspection and has plenty of time before it expires.

[rtry9a]

Re: CNG tanks never expire?

Id question if the real issue is safety or a combination of planned obsolescence from manufacturers and uninformed regulators. There is virtually no data that supports a rupture danger threshold of older undamaged tanks; Id welcome any documentation to the contrary, but I have not seen anything so far.

[cowboy]

Re: CNG tanks never expire?

I think you are right but and it is a big but what if it is your kid or wife that gets hit in the head with a low flying tank you only get one booboo when fooling with this kind of pressure myself I trust type 1 tanks and they can be used forever as long as they pass there test . but they are heavy but no one has come up with a way to test the plastic ones without destroying them. now dont get me wrong I do have some of the plastic ones in use .the real deal is to get the pressure down such as with corn cobs and chicken feathers if they ever get that to work then tanks would be cheap and could be type 1 as they would not have to be as heavy to handle the lower pressure.

[larrycng]

Re: CNG tanks never expire?

If someone had the money, take some expired tanks to a group like Power Tech Labs and have them Hydrostatically tested or run them throught the NGV 2 test cylce, that would give you some data. Then run the tanks through a destructive test and see how they measure up. Of course you probably wouldn't know how many pressure cycles the tanks had been subjected to during their 15 year service life, let alone how many times they had been over pressurized or subjected to temperatures over 180 deg, F. We know that the Comdyne and EDO tanks had problems.

I've seen the results of various tests from a testing house and will go with the NGV-2 or DOT 304 standards. And then there are those who may not be as forth coming as they should be, who will try sell tanks that, in reality, they do not know the complete history of and are trying to make a buck off of.

Larrycng

[wannabecng]

Re: CNG tanks never expire?

I am looking to buy a CNG (probably Civic) and the cost of new definitely has me looking at the used market. I have queried a few owners about the tank and responses have been 100% "not an issue" or "never heard of that". So, my question to this forum has to do with the owner or dealer being able to produce proof of when the tank will expire and/or last inspection date; should they be able to do that? Also, if a tank is reaching the end of its useful life, what is an approximate cost to replace? The used CNG civics advertised right now in SoCal are predominantly 2001-2005 with mileage between 33k-118k. Am I better off waiting until I can scrape together $27k for a new one? I'm planning to look at two used models tomorrow and a new one on Monday. This tank issue is the most troubling and confusing element of the leap into the CNG world and I just don't want my leap to be into the abyss. Thanks!