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Tank Safety - What You Can Do

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  • #16
    Re: Tank Safety - What You Can Do

    I joined back in March but haven't been active on the site. I rediscovered it a few days ago and was reminded what a great place it really is. I plan to become a regular user and hope to fiqure out a way to pursue a new career in the CNG field. With that said, I have a question I hope someone can answer. If a CNG tank has 1 and 1/2 years remaining on the 'DO NOT USE AFTER THIS DATE' label and a tank inspector is called to do a 3 year inpection do they put a 3 year sticker on the tank or do they make the inspection good for only that period which is left on the tank?


    • #17
      Re: Tank Safety - What You Can Do


      Technically the inspection is only good for the period which is left on the tank. I usually write the expiration date of the tank on the inspection form that I give to the vehicle owner and make him/her aware that the tank will expire before the 3 year inspection.
      Mountain Green, Utah
      2003 CNG Cavalier
      2003 CNG Silverado 2500HD


      • #18
        Buyer beware - After posting questions to eBay sellers auctioning a vehicle with expired tanks over the last year, I called eBay to ask why the answer is not being posted so that other bidders can see that they are in for a $4000 tank job.

        IT TURNS OUT THAT THE SELLER CAN CHOOSE TO SEND A PRIVATE REPLY OR TO HAVE THE ANSWER POSTED ON THE AUCTION. I can categorically state that none of the sellers chose to have their expired tank answer posted to the auction for others to see. HOW DECEPTIVE!

        So it would seem that the only way buyers of NGVs will learn that the tanks have an expiration date is if this feature of the fuel tank is publicized more widely. A number of buyers have contacted me asking how to fix the tank problem. Had they known, it would have changed their buying decision. And I guess that this only serves to encourage anyone looking at something out of the norm to learn as much as they can about it in advance.

        The answers the sellers have sent me privately have been varied (date of response YYMMDD):

        161119 All vehicles are sold "as-is where-is."
        161011 Tank expired 2015. Not sure if the tank needs replacement/nerver had any problems. Many people drive on expired tanks.
        160930 i do not know , but if this is a major concern to you please don't bid on this truck ....i have never heard of this before
        160928 What are you talking about?
        170312 I really do understand ALL of that, although I do appreciate your verbose and thorough assessment/ assistance. It REALLY is not there. Sorry, I wish it were. - Jay
        170320 I have no idea what a new tank costs. Stated in the ad, WSU has never used the CNG system and do not know if ever worked when WSU bought it. They have always used unleaded gasoline. Thanks
        170320 no, the 1998 FORD F-250 has DOT bottle that can be hydo tested for less a hundred dollar a piece
        170323 CNG has never been used on this vehicle. I can't answer other questions regarding the CNG.
        170405 Thank you for pointing that out. We are selling the vehicle AS-IS.
        170428 I will look at the tank and update the auction as necessary.
        170525 The picture shows expiration date. I will add the expiration date to the ad. I can't post the cost since I do not know.
        170525 Not sure... I don't know about that sticker?...
        170618 (2001 Dodge Ram) The tank has never been replaced and to my knowledge is not expired. Additionally I just looked at the tank there are no visible disclaimers or expiration notices visible from under the vehicle. I would need to do further research but it may sound as though you know more. Would you like to enlighten me? Upon additional research this vehicles cylinder life is 20 years and there after needs recertification every 36months or 36,000 miles to keep it in service. So to answer your question it does not need replacing.


        • #19
          Appreciate your efforts to educate those selling or assisting in the sale of vehicles having expired tanks.


          • #20
            This is a very similar situation to the UK. Here we have an annual roadworthiness test (our MOT test), I'm sure you must have something similar. Yet, with 3-4 cars in the whole country, CNG cars and their tank expiry forms no part of any test requirement. Seems despite years of CNG cars, and many knocking about, your system is no more up to the job than ours. Yet you have many more cars.

            To us Brits the stereotypical American lives in a more risk adverse society, and is infinitely more litigious. Seems here, this is not correct.
            Last edited by BritCNGUser; 07-10-2017, 02:39 AM.


            • #21
              These replies from sellers to the Is The Tank Expired question were eye-openers. Credit is due to seller of US Postal Service bi-fuel van that removed the expired CNG tanks prior to sale:

              170715 Tanks have been removed. Don't know what cost to replace. Thank you, USPS Vehicle Sales QAL No - 6250-2689 Inventory ID: 8932307

              However, the used car dealer of this next listing under-estimates the replacement cost - by quite a bit. Seems he was told tank life has to do with mileage. He provided a name, phone, and email which I can provide if I am sent a private message through the forum:

              170715 I just found out about it and spoke to a few people about it. I am going try to get the tank inspected and certified because one person said that because it has such low miles the tank is probable good.. If you want it as is I would sell it for $5000.00. By the way I read about 25 posts that said it costs $1000.00 to replace the tank.Google it.


              • #22
                More replies from online auction sellers to the - Is The Tank Expired - question:

                Tank is not an issue (1998 GX).

                The CNG tank is original equipment (1998 GX), the label you refer to is to the best of my knowledge only applied to fleet vehicles. If it were a hazard I am sure California DMV would not allow the vehicle to be registered for the roads in California. If you have proof to the contrary please provide it.

                As I understand it the tank does not need to be replaced for private ownership, only commercial use. The tank is original (1998 GX).

                The car is in good condition, runs great. the fuel tank was inspected in Sept. 2014 and is due to be inspected again (2003 Ford CrownVic).

                The auction seller steered me to an article in in which he should have found the correct answer to the expired tank question:

                Tanks cannot be recertified after reaching the expiration date set at time of manufacture and must be taken out of service. Although NGV standards officials initially considered a process for recertifying older tanks, liability and technical challenges scuttled the idea.

                ..if you continue to use a tank that is past its expiration, then the liability is all on you.

                The tank should be destroyed upon its expiration because there is no re-hydrotesting of CNG tanks and returning them back into service,



                • #23
                  Another reply from an online auction seller to the - Is The Tank Expired - question suggests tanks do not expire in some states (not true):

                  I do not know how much new tanks cost, however the expiration dates on tanks is a estimation from the manufacturer based on corrosion resistance, when the standard went from 15 years to 20 years the structure of the tanks was not increased only the corrosion inhibitor. these tanks (in auction) were filled with good dry fuel (-80 deg F dew point) Ohio is not a State that requires replacement, I do not know which States do


                  • #24
                    Being a person that lost a customer because a disregard for tank safety, I take it seriously. I believe it is DOT that is the governing body of tanks not the state. Sadly because of the limed market tank safety is not taken seriously by states that do annual checks. In California Inspections are up to the owner. The only way that a vehicle is required to have a safety inspection is if is sold through a dealer.


                    • #25
                      I don't want to diminish the issue of tank safety but did you lose the customer because of an issue with an expired tank?


                      • #26
                        No, it was because of a damaged tank that was no retired properly. In Pasadena the tank was improperly installed and obviously not inspected. The original Comdine explosion could have been avoided with routine inspections. I cannot remember the causes of the Corona fuel station tank failure. I believe that the average person is too cavalier about the potential hazard form high pressure storage.