Ok, stupid question!

  • Views : 326
  • Link

    estrike
    Participant
    Member

    Ok, here goes a stupid question. Please don’t chastise me for it.  I’m looking to buy an air tank to use to fill up my guns in the field.  I’ve read that these tanks have a life span of 15 years.  If that’s the case then why are people selling used tanks on eBay that have manufactured dates older that 15 years ago.  Aren’t these tanks obsolete? Or are they safe to purchase?  If a tank is over 15 years old will companies refuse to hydro test them??

    Link

    brawler1588
    Participant
    Member

    Not a stupid question, out of the 15 year life span they cannot be hydro tested the reason people buy them is if the tank is in good condition you can refill yourself if you have a compressor. 

    Link

    Eaglebeak
    Participant
    Member

    If you are talking about carbon fibre or composite cylinders then yes they are past their legal use by date. There is an expensive process that can extend the life up to a possible extra 15 years but for the average Joe it is not economically viable. Metal SCUBA tanks have no such expiry dates but must be tested regularly. If you see a CF bottle with a birth date that is  near or past 15 years old, give it a wide berth.

    Link

    estrike
    Participant
    Member

    What does that mean? “Give it a wide berth”

    Link

    hawkeye69
    Participant
    Member

    estrike

    What does that mean? “Give it a wide berth”

    Steer clear of it, avoid it.

    Link

    boscoebrea
    Participant
    Member

    It is a saying,"like don't go there"…I'll give it a bye…stay away from..etc..got it,another saying.A berth can be a place to sleep or where ships or boats "park"..or like "give it room" like a rattlesnake,a skunk…or whatever,don't go near it.

     

    Link

    estrike
    Participant
    Member

    Ah, ok!

    So I’m ok with buying metal tanks that are older than 15 years as long as they have been hydro tested recently, correct?

    Link

    oldspook
    Participant
    Member
    Link

    Spartan
    Participant
    Member

    estrike

    Ah, ok!

    So I’m ok with buying metal tanks that are older than 15 years as long as they have been hydro tested recently, correct?

    That's generally true for aluminum or steel SCUBA tanks, and with the hydro test being within the last five years. However, those tanks typically fill to much lower maximum pressures and can be quite heavy and bulky. In my opinion, CF wrapped SCBA tanks are by far the better option.

    Also keep in mind that ANY used tank you buy (even if it is well within the lifespan and hydro tests dates) can still fail it's next inspection or even be unfit for use at the time of purchase based on previous handling. That's a risk you take when buying used tanks regardless of their current certifications.

    Link

    Eaglebeak
    Participant
    Member

    It's probably best that you do a little research before you decide what is best for you. Google is your friend. There are traps and pitfalls with buying used pressure vessels. For instance, there was a batch of aluminium SCUBA tanks made in the nineties that were made from dodgy alloy that are still kicking around. I think one or two even burst whilst being filled. If you buy one of those, nobody will fill it because the dive shops have been warned about them and serial number will give it away. Buying a SCUBA tank that is out of test can be a cheap option but it will be a lottery. My brother was given an old steel aqualung tank of Mike Nelson's (Loyd Bridges)Sea Hunt vintage. He sent it off for testing, expecting to get it back in two halves. It came back with a new coat of paint and re certification. As mentioned above, an SCBA tank is the best option in this game but a lower pressure SCUBA  tank can be a cheap alternative if you have a gun with a lower max fill limit.  

    • This reply was modified 3 days ago by Eaglebeak.
    Link

    Joer
    Participant
    Member

    Here's what I did with an old tank.  January last year, I bought a 2006 MSA tank off of Ebay that had about a year left on it's every five year hydro and two years left on it's 15 year certification.  My plan was to buy a compressor and fill it myself.  I had the tank reinspected and hydro'd at a local fire equipment dealer in a town near mine.  This company is listed as an official DOT hydro site.  The tank passed hydro and I was told it is in great shape based on the visual inspection.  I then took it to a local dive shop to have it filled.  The shop could not go past 3000PSI but that was fine for me.  This allowed me to fill it past 4000PSI without adding a pressure maintaining valve to my fill rig.   

    The bottom line is the test gave me confidence that the tank is good. 

    Link

    jdh2550
    Participant
    Member

    I have bought 2 used scba tanks from a fire fighter store here in PA.  Average cost is $50 per year of usable life left.  They come filled.  If the guy selling me the tank is willing to stand beside it when he fills it, that's good enough for me.  He knows more and has seen more with these tanks than I ever will.  I have 2 tanks (at $100 each) and that gives me enough high end air pressure for lots of hunting/range time.

    This is a low cost solution for me to use PCP's.  I'm very comfortable with my purchase and tank conditions.  You may feel different though.

    Link

    Saltlake58
    Participant
    Member

    No stupid questions when dealing with 4500 PSI.  High pressure air can injure or kill.  

    Here's a video that shows what a "Failing" tank can do.  Granted, this tank failed due to gunshot wound.

    Regardless, when a tank fails, I'd rather be somewhere else.

    As for the 15 year lifespan, that's Department of Transportation if I recall.  All sorts of regulations around the HPA tanks.  15 years is the legal life span, not necessarily the actual life span.  Key is that once it's older than 15, there's only one way to extend the life span with a new kind of Hydro Testing that the US Navy spearheaded.  PA sells the extended life tanks, https://www.pyramydair.com/s/a/Air_Venturi_Life_Extended_Carbon_Fiber_Tanks_4500_PSI/8677

    With current costs, it seems an expensive way to extend the legal life of a tank.  

    Anyway, tanks under the kind of pressure we use for airguns, the expansion and contraction of the tanks over time may cause cracks, and cause an eventual failure.  No guarantee either way, so it's kind of a crap shoot.  

    Good luck on the hunt for tanks, it's always an adventure

     

Viewing 13 posts - 1 through 13 (of 13 total)

You must be logged in to reply to this topic.