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Hey guys any idea what kind of pressures these kind of drink bottles can take?
Cheers

jmadden91 wrote:Hey guys any idea what kind of pressures these kind of drink bottles can take?
Cheers

Never tried it. I would recommend hydrostatic testing to find out. Fill one completely full of water and test under pressure at 150% to 200% of the max you intend to use it. For a 100 PSI launcher the test pressure should be 150-200 PSI. Since they are much thinner than pressure stuff, I would think the rating would be lower than that of an spray can due to the flat bottom. Maybe 60 PSI tops.

Awesome thanks heaps mate. I dont have the equipment to test it. But I have just tried firing with it on. I dont have to worry about the pressure yet cause my gun leaks like a sieve. I do have an empty fire extinguisher downstairs that i think i will put on instead. I just thought it could be a decent cheap option.

jmadden91 wrote:Awesome thanks heaps mate. I dont have the equipment to test it. But I have just tried firing with it on. I dont have to worry about the pressure yet cause my gun leaks like a sieve. I do have an empty fire extinguisher downstairs that i think i will put on instead. I just thought it could be a decent cheap option.

No special equipment needed. Fill the water bottle with water and install it. Pressurize as normal, higher if possible. Operate it below the test pressure with a safety margin. For example my ABS test cannon (the apple cannon) is tested to 85 PSI and operated in the 30 to 60 PSI range.

They use them quite a lot in france. I think this guy
http://www.spudfiles.com/forums/d4-fren ... 17748.html
said up to 10bar.

Don't forget that those bottles probably have a glass inside. (Atleast my aluminum bottle has it...) They use this glass "inner bottle" to create a vacuum between the aluminum and the glass so that the fluid that's inside is well insulated.

Don't forget that those bottles probably have a glass inside. (Atleast my aluminum bottle has it...) They use this glass "inner bottle" to create a vacuum between the aluminum and the glass so that the fluid that's inside is well insulated.

Mate thats a thermos. Mines just a standard drink bottle


@Biopyro
Oh awesome. Are you sure they aren't C02 Bottles though?

@Technician
Thanks mate i might have to try that. Sorry for the noob question but what's the point of the water?

The water doesn't store much energy because it's essentially incompressible. Gases do store a lot of energy and consequently if a burst happens it can be dangerous.

I'd suggest against using something designed for drinks and for using something designed to be pressurized. The bottom of the container likely isn't designed to handle the stress well. That's not to say that it won't handle any stress, just that it likely is a poor choice.

Aluminum cylinders designed to be pressurized are cheap. I have one by this company: http://www.catalinacylinders.com/lp.html

The 600 psi burst pressure ones have a rating of 240 psi, the 1250 psi burst pressure tanks have a rating of 500 psi, and the 1440 psi burst pressure tanks have a rating of 576 psi.

Give them a call if you want to order one.

jmadden91 wrote:
@Technician
Thanks mate i might have to try that. Sorry for the noob question but what's the point of the water?

Water doesn't compress. As a result when hydrostatic testing tanks, they may split and leak but don't explode because it doesn't expand when released. Try it with ballons. Pop an air filled ballon. It's noisy. Now pop a water balloon. The splat is from the rubber, not the release of compressed air. It's not loud. A metal tank failing with air can be very dangerous. A failing metal tank of water won't throw stuff far.

Well makes sense. I will definitely give that a shot if i cant get this Fire Extinguisher. It will be better regardless. Thanks again though tech

Brettel is absolutely correct.

With hydrotesting, when/if a failure occurs, there is a very small "pfft" and that's it. It's not dramatic at all, even at over 6000psi. Been there, done that.

If you fill a vessel with water, and then pressurize it with air(or co2, etc.), you are defeating the whole reason for hydrotesting.

The air used to pressurize, is STORED energy. It WILL force the water out through any failure,..at pressure.

Ever heard of a water jet cutter? A lot more pressure, but if you think that you're being "safe" by "only" pressurizing with a gas, you are dead wrong.

Failures with stored energy, will be dramatic, and dangerous.

Please don't fool yourself into believing otherwise.

lol ok thanks mate.

@btrettel
THanks for the help mate. And Im in Aus so i probably wont get one shipped from America but thanks for the link mate

I have tested a french bottle (like the one biopyro mentioned) to 21bar.
The flat bottom will become convex around that pressure.

I tested the bottle with air pressure but filled with over 90% water, even though the air will expand pushing water, there is only a few cubic centimeters instead of over a litre of high pressure air. So I do consider this to be safer in my situation, allthough there are other things to consider, like the fact that the bottle could become a hard, high inertia, high powered water rocket.

I have the feeling water jet cutters are fully hydraulic though, and at close range a vessel failing under hysdrostaic pressure will be dangerous and the fluid may cut depending on the shape and size of the breach.

But yeah gases make it much more dangerous.

Depending on your preparation even hydro testing can be dangerous. When I was last doing it I didn't fasten anything down, just put it in a bucket, and when the plug blew out I got a nice bruise from the hose whip due to contained energy in the hose, even though there was no air.

So just make sure you have things secured well and covered. Obvious, I know .

Gippeto wrote:Brettel is absolutely correct.

With hydrotesting, when/if a failure occurs, there is a very small "pfft" and that's it. It's not dramatic at all, even at over 6000psi. Been there, done that.

If you fill a vessel with water, and then pressurize it with air(or co2, etc.), you are defeating the whole reason for hydrotesting.

The air used to pressurize, is STORED energy. It WILL force the water out through any failure,..at pressure.

Ever heard of a water jet cutter? A lot more pressure, but if you think that you're being "safe" by "only" pressurizing with a gas, you are dead wrong.

Failures with stored energy, will be dramatic, and dangerous.

Please don't fool yourself into believing otherwise.

Gippeto is correct on this one. However for the relatively low pressure of the water bottle, the amount of stored energy in the applied pressure with a gas is relatively safe at under 200 PSI and a small container.

At higher volume and more important at higher pressure where each doubling of the pressure increases energy 4 times, this is not recommended at over 150 PSI.

Basically anytime you are exceeding the energy levels of a liquid filled 2 liter pop bottle (hot soda on a hot day bursting) you are starting to get into dangerous energy. At lower energy, the danger is minimized.

This is why the ABS DWV cannon has not been tested to failure. I was keeping the failure energy in a sane range with air. With water in it and using air to pressurise, I still would not attempt to test it above 200 PSI. With water only and no air, testing to failure is no problem.

Use some common sense and understand the amounts of stored energy that may let go in sudden fashion.

Aluminum water bottle, filled with water, hand pump.. failure should not be too dramatic. Safety glasses and a safe distance is recommended and possibly a sheet of plywood for a blast shield.

I have heard of a water jet cutter. A high energy stream of water collides with air and energy is dissipated in a short distance. For example a pressure washer can remove all kinds of stuff off a sidewalk. If I stand 10 feet from one and I am directly blasted, I'll get a nice cooling mist. Distance is your friend. Don't sit on the vessel being tested.. Use some common sense.