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Tank Danger, or is it.

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This topic contains 9 replies, has 6 voices, and was last updated by  hoot 4 years, 9 months ago.

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  • #18672

    iride
    Participant

    No place to really talk about tanks so I will put it here.
    When I was looking around for a 6000 PSI nitrogen tank everyone said I was nuts, I even tried to get around it by saying I owned a small 30×50 motorcycle shop and that’s were the tanks would go, No go, I did have one taker but it was crazy expensive over 100 bucks a month , ( I do have a shop)
    My question is, I keep my tank inside in my office,
    Has anyone ever heard of some one getting hurt buy a exploding C/F tank ?
    I could not find one case?
    I have got a compressor coming , and was planning on buying a small c/f tank off Ebay, Easy fast shooting so I do not have to carry my great white tank around, Is it safe to buy a used bomb?
    We fill our guns up to 3200 PSI , or they so over built we do not have to thank about it?
    Mike

    #219388

    surfski808
    Member
    quote :

    I keep my tank inside in my office, Has anyone ever heard of some one getting hurt buy a exploding C/F tank?

    A carbon fiber tank is unlikely to fail by catastrophic rupture or explosion. A slow leak or partial release of a high speed jet of gas is more likely. To answer your question, yes people have been hurt before. Here is one example: http://youtu.be/wEgt41AJaU4

    Possible Dangers::
    A high speed jet of gas can turn a tank into a high speed projectile (as shown in video).
    A high speed jet of gas can cause serious eye injury.
    A slow leak of pure nitrogen being released in an enclosed area could pose a danger to life though asphyxiation.

    quote :

    Is it safe to buy a bomb (used tank)?

    Yes as long as you do some due diligence and use common sense.
    – Avoid expired or soon to expire tanks. Most CF tanks have a 15 year life span. .
    – Avoid a CF tank that shows signs of de-lamination, layer separation, blistering. or pressure bulges.
    – Avoid filling the tank beyond it’s max fill pressure as shown on the side of the tank.
    – Inspect any O-rings and replace if necessary
    – Have the tank hydro-tested for piece of mind, it should cost no more than $30.

    quote :

    When I was looking around for a 6000 PSI nitrogen tank everyone said I was nuts,

    I had no problem leasing a 6000 psi cylinder from a supplier where I live so you should be able to as well. I think you just had bad luck and ended up speaking the wrong person. My suggestion would be to call again and speak with a different person. Eventually, you will find someone who more interested in making a commission off a sale than turning your business away. If asked, stick with the story that you need it for your motorcycle repair shop to weld and fill tires.

    #219389

    keyser-soze
    Member

    Are you planning on buying a used FD SCBA tank? Here are some facts about them if you are. They get hydro tested at 7500 psi The working pressure is 4500 PSI but they are routinely filled to 5K. This is why they hydro them a little more than the 1.6 times the working pressure commonly used in the industry and required by DOT. The bottles are overfilled because often times they get hot because the bottles are filled quickly and they know the pressure will fall. A little extra air is a good thing when a 30 min 4500 psi bottle is really only about 12-15 minutes of working time. They get tested every 3 years. Depending on the department they may get beat or they may just sit. Most FDs get rid of them after 3 hydro cycles. The only time I have known them to fail is where the bottles were exposed to something that destroyed the carbon fiber’s integrity. There was a case about 15 years ago where a FD responded to a chemical fire at a plant. The bottles were exposed to nitric acid and hydrochloric acid. The bottles were not properly decontaminated. It was later theorized that the two acids reacted with the methyl acrylate used to bond the carbon fiber and the bottles exploded. The side compartment where the bottles were kept was demolished. No one was hurt due to the fact that the Engine Company were asleep when the bottles exploded.

    After this incident manufactures began to rap the bottle with a polymer which protects the bottle from physical and chemical damage. So the moral of the story, firemen wouldn’t wear them on their backs in hostel environments if they were that fragile.

    #219409

    iride
    Participant

    Thanks guys this really helps me out.
    I am looking for a place around here that can test tanks if I buy a used one,
    I know the paint ball people really screwed up a lot of places around here that used to fill tanks.
    The few people that have seen my great White were really impressed by the quality of it but refused to fill it..
    Like I say I got my own compressor coming , But I still need to get my tanks tested if I buy used…..
    Mike

    #219417

    secoda
    Participant

    When I took scuba diving at the University of Illinois many years ago someone stood up an aluminum tank and it fell over causing the valve assembly to separate. The tank shot through a cinder black wall and bounced around in an office. No one was hurt but it was only a 3000 psi tank. They had a rule that anyone caught with a standing tank was out of the class immediately. There is a lot of energy in a full 6000 psi tank. There have been several scuba tanks explosions but the ones I know about had pure O2 in them or close to it.

    #219447

    Mike,
    If you are planning on filling a 6K bottle with your compressor, you need to be very careful with that if you are using plain old air. At those pressures, air should be treated like oxygen. If you are using one of the compressors like the shoebox that compresses air from a normal air compressor, be sure you use an oil-less compressor for the first stage. Oil and high pressure air don’t mix well—explosions can result.

    Also, I have seen some very catastrophic failures of carbon fiber tanks. I build high pressure gas equipment and I supply it to many customers. One application that I furnish equipment to is a third part engineering company.When they test these CF tanks to destruction, a leak is in fact not the failure mode most often encountered. When they let go, they fly into a million little pieces and the release is a devastating amount of energy. Since you’re in West Texas, heat can be an issue for you. A full carbon fiber tank left in your truck or in the trunk of your car can overheat and explode. Such an event will indeed cause major damage.

    #219449

    keyser-soze
    Member

    Saltwater,
    a fire department CF tank will not overheat and explode. Trust me I have a lot of experience with these bottles they are built for a more extreme environment than the trunk of your car. They are kept in trunks all the time.

    I didn’t think he was planning on filling the CF bottle to 6K, he wants a 6k nitrogen tank like the ones found at a welding shop, then use Joe B’s nitrogen setup to fill his smaller bottle for traveling. I think the 6K nitrogen tank and CF tank were two different subjects. A FD CF tank will not hold that much pressure(6K PSI), above the valve is a pressure release nut, it will off gas at just around 5300 PSI.

    #219463
    quote keyser soze:

    Saltwater,
    a fire department CF tank will not overheat and explode. Trust me I have a lot of experience with these bottles they are built for a more extreme environment than the trunk of your car. They are kept in trunks all the time.

    I didn’t think he was planning on filling the CF bottle to 6K, he wants a 6k nitrogen tank like the ones found at a welding shop, then use Joe B’s nitrogen setup to fill his smaller bottle for traveling. I think the 6K nitrogen tank and CF tank were two different subjects. A FD CF tank will not hold that much pressure(6K PSI), above the valve is a pressure release nut, it will off gas at just around 5300 PSI.

    Keyser, My experience with CF vessels is oil patch related and mostly a LOT bigger than these FD tanks.

    I mentioned the 6K bottle only as advice NOT to fill it with air. I assumed he’d probably rent/buy a bottle full of nitrogen… However if you do own your own 6K bottle, it is dangerous to take it up that high with air. I’ve had my gas boosters (that are air operated) used to amplify shop air catch fire internally and have a “melt down” at pressures less than 5K when boosting shop air from a centrifugal compressor… lots of oil in that air.

    I shoot with nitrogen pretty much exclusively as I have it readily available. I have a CF tank that I refill with nitrogen. I bump it to 4500 psi and let the temperature settle a bit, then top it off again. It’s nice not to have to worry about moisture in the guns.

    #219467

    iride
    Participant

    Thanks, But I had to give up on the nitrogen a while back, Way to much hassle and money,
    I bought a New Great white tank about a year ago, My 4500 fill is about 35 bucks, I started looking at compressors very hard a few months back.
    Bought me a Jim Sheldon compressor that is being built now, Should be ready end of this month, Three week build,
    I would like to buy me a small 4500 psi bottle (used) to just toss in the truck and go shoot,
    I did talk to someone about testing a used bottle, and they said , We just fill the bottle up to 5000 PSI if it holds up , Its good to go…
    I may have go talk to the scuba shop over in Midland, (35 miles away) about safety testing. The scuba shop can only fill to 3000 PSI, I already ask.
    I have learned that it takes foot work, Phone calls are no good, You got to go talk to the people. Just let them no your an adult , with a hobby , and your not going to grease the nipple up on your tank to keep it from leaking. (paint ball people).
    sorry for the long post , But this high pressure air and tank , Has put a fart in my hobby,,,
    Soon to be relieved by my compressor ,
    But I will be looking for a small 4500 PSI bottle to fill with MY OWN COMPRESSOR and the Great White will be full 99% of the time, 😀 😀 😀
    and you guys that get cheap fills, and can get nitrogen, count your self very lucky…..
    Mike

    #219484

    hoot
    Participant

    Let’s not forget these scuba/scba tanks all have a “blow out” valve built into the regulator. It looks like a small bolt screwed into the side of the reg. It’s designed to pop and release when the pressure goes beyond the rated fill pressure for that tank. In the scuba tanks it’s just a copper plate tested to blow out when the pressure goes substantially above the safe fill levels. Usually they are rated at 3k psi, or 4k psi for the high pressure steel tanks, and this number is stamped on the top of the screw-in bolt.

    Hoot:

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