At what PSI does a plastic soda bottle explode? (home CO2 carbonation)

Good grief: If a bottle broke open it because it froze, that had to do with the expansion of the contents, not the carbonation. You can do the same thing with plain water for pete's sake.

Many people hoodwinked here - it had nothing to do with the carbonation and knowing the exploding point of the bottles isn't much use when it's pressure from freezing and expanding contents inside the plastic, and even less to do with home carbonation. When liquid cools, it expands - which can burst bottles, metal pipes, whatever.

Reply to
Twayne
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I would advise to have your pressurized bottle located in a location where an explosion is tolerable. I would not bet my life or the house on the pressure to be used to not exceed what it should not exceed, or the bottle to not have a flaw or damage (possibly incurred after its manufacture) that causes it to fail to withstand what it's supposed to withstand.

- Don Klipstein ( snipped-for-privacy@misty.com)

Reply to
Don Klipstein

Eyeball-estimate - roughly a torus that on largish side has a tubular cross section whose diameter is 20 cm, and with a 50 cm diameter of the tube's "centerline". Volume of such a "largish tire" would in cubic centimeters be 20 squared times pi/4 tomes 50 times pi, or 49,348 cubic centimeters. Divide by 1,000 to get liters - about 49.

That does sound to me large for a tire, maybe about right for a tire for a large SUV. Also, most car and SUV tires are not inflated past 36 PSI.

50 liters at 36 PSI, if compressed to 150 PSI, takes up 12 liters.

One more thing - CO2 has slightly different dynamics in compressibility than air does, due to its lower specific heat ratio. CO2 at 32 PSI in a

14 PSI atmosphere has the same "stiffness" as air would have at about 28.5 PSI. The vehicle's ride and "road feel" and how much the tires get mashed by bumps and potholes would be as if the tires were underinflated about 11%. The specific heat ratio of a gas alters its compressibility when it is compressed or expanded quickly enough to have its temperature respond to the change in pressure rather than being held by heat conduction to the ambient temperature.

However, the wear rate and wear pattern would be determined more by the pressure alone. Compensating with a higher pressure would concentrate the wear towards the "centerline" of the tread.

Also, pressure alone contributes to much of the stress that parts of the tire must face and the shape of the tire and its contact patch when it is supporting a load. This affects its traction on wet roadways at higher speeds. These factors can severely limit use of higher pressure just because the gas is more compressible in a "dynamic sense".

- Don Klipstein ( snipped-for-privacy@misty.com)

Reply to
Don Klipstein

I would be leary about the ability to withstand 150 or 120 PSI being valid at the highest temperature that can be encountered in this application. I have had experience with boiling water causing PET soda bottles to soften and go out of shape without any significant pressure at all.

- Don Klipstein ( snipped-for-privacy@misty.com)

Reply to
Don Klipstein

There are many bike tires rated to take 105, even 110 PSI.

A decent floor pump can achieve 110-120 PSI in the hands of most serious cyclists and bike mechanics.

Frame-fit pumps for "road bikes" in my experience can achieve 130-150 PSI. Back when I worked a messenger job, I often pumped my rear tire to

130-140 PSI so that I could carry heavier loads (80-150 pounds) on a rear rack that I built for the purpose. I made more money that way, and the motor vehicle messengers in my company were happier to get less business in the areas where parking was more impossible.

Experience taught me which tires were able to take such abuse, and which ones were not. (And an extra-loud *KABOOM* would sometimes occur at a very inconvenient time, such as halfway through a 2 mile delivery run, or while my bike was parked in my home at 5 AM. Some messengers keep their bikes in their bedrooms, although I did not combine that with a tire rated 110-115 PSI and inflated to 130-140 PSI.)

- Don Klipstein ( snipped-for-privacy@misty.com)

Reply to
Don Klipstein

In , J. Zappacosta said in part:

Why is it so popularly mentioned on the web how to blow up soda bottles with caustic chemicals? (This is far from the first time I have heard on the web and in Usenet how to do that with caustic chemicals of one sort or another.)

If someone has to make a big bang and maybe attract attention of the police, would it not be more wise to use something not so caustic, such as vinegar and chalk, or better still water and a bunch of Alka-Seltzer tablets, or a long hose and an air compressor or a long hose and a bicycle pump made to achieve higher pressures used in road bikes and track bikes? Get someone good and strong to operate the bike pump if much more than 150 PSI is needed to get the cars coming in with red and blue flashing lights?

- Don Klipstein ( snipped-for-privacy@misty.com)

Reply to
Don Klipstein

Strongly agree!

My dad was a safety engineer and often testified at trials as an expert witness. Soda bottles have a rich history of litigation. If they are dropped just right in a store, for example, the cap can blow off with enough force to put out an eye, and it's happened many times, it's not just a freak one-off occurrence. Injuries have lessened with plastic v. glass bottles, but they have not vanished entirely.

Much engineering has gone into designing safer bottles (the odd star-shape of the bottom is designed to "pop" visibly when dropped and provide some visual warning that the bottle is overpressured. The screw threads on the cap are interrupted for the same reason). Still, there are soda bottle accidents every year in the US. Many are caused by shelf stockers insisting on filling high shelves beyond capacity, making a floor drop from considerable height all but certain.

Overpressurizing them for fun with kids around seems to be a pretty silly idea. But they do make passable silencers for pistols if attached correctly.

Search for "soda bottle eye injury" on Google to find many tales like this:

"We have come across six patients of ocular injuries due to CBB explosions during a period of nearly two years. All the cases had unila­teral involvement, right eye in four cases and left eye in two cases. All of these patients had severe visual loss. Initial visual acuity, after the injury ranged from loss of perception of light to finger counting at two meters distance. In one case the eye was badly mutilated and had to be enucleated. In five cases, the injury was caused by glass splinters, while in one case it was due to the cap of the bottle. The injury due to the bottle cap was interesting in that it left a clear impression of its crenated edge on the skin of the lids and the cornea which gives some indication of the force of the impact. In four cases the CBB exploded without provocation."

Source:

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-- Bobby G.

Reply to
Robert Green

Then all we need are 6 two liter Coca Cola soda bottles! We could just as easily fill them up with compressed air as with C02. Sounds interesting. I'm waiting for the you-tube video of the manifold!

Reply to
LM

All very interesting especially the interrupted screw threads!

Never even noticed that until I just now took a look.

I suspect it makes the (over)pressurized air blow by the gaps, right?

Reply to
Elmo

They do blow up and with considerable force. My neighbor's friend works in the bottled gas business. His company makes dry ice. He gets it for nothing and uses it for keeping his beer cold when he comes out here for the weekend. He likes to make loud noises by dropping dry ice into plastic pop bottles then sealing them up.

Better than the big firecrackers we called blockbusters when I was a kid.

You wouldn't want one of those bottles next to your crotch if it decided to go boom.

SM, don't try to impress the kids at church. Someone will get hurt.

LdB

Reply to
LdB

Lots of experience at rec.crafts.brewing.

If you are just carbonating drinks, there is no reason to go over 50 psi unless you are in an extreme hurry. Why bother?

Reply to
Bob F

As long as you are only trying to carbonate something and not force an explosion, wouldn't only a few PSI be adequate?

Mysterious Traveler

Reply to
Mysterious Traveler

Maybe I was a bit premature - other links in the article that I responded to did show soda bottles being blown up by an air compressor and apparently also by a bike pump.

- Don Klipstein ( snipped-for-privacy@misty.com)

Reply to
Don Klipstein

Yes. My regulator is faulty. I thought it was the gauges but when I put a second set of gauges on, I realized the regulator isn't working. It's always at something over 150 psi.

It's not a big deal, as Coke confirmed by phone all their plastic 20oz to 2 liter PETE bottles are safety tested at the "industry standard" 150 psi and some are even tested to 250 psi.

I've successfully carbonated, so far, water, grape juice, pinot noir wine, lemonade, and orange juice. The attempt at carbonated milk and carbonated yogurt weren't the most stellar of achievements though; neither was the ice-cream carbonation nor the strawberry fruit carbonation.

But, I keep learning, e.g., here they actually test the burst pressure of a

2l coke bottle (and show a slo-mo video with the pressure counter in the corner):
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Maximum Operating Pressure is called MOP (which is what you do when you reach it)

- Test 1: 2 liter coke bottle burst at 190 psi (the bottle actually stretches lengthwise in the slow motion video)

- Test 2: 1.25 liter coke bottle burst at 185 psi (in slow motion you see the cones on the bottom stretch out to almost cylindrical before bursting)

- Test 3: 1.5 liter coke bottle burst at 175 psi (always the bottom or sides give out before the cap does)

- Test 4: 1.25 liter coke bottle with duct tape burst at 195 psi (for the first time, the cap sprunk a leak but the failure mode was the package)

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A soda can is able to withstand over 100 PSI

- A 6.5-ounce glass soda bottle can withstand 225 PSI

- A 16-ounce glass soda bottle can withstand 175 PSI

- A PET soda bottle can withstand 150 PSI--the industry standard

Reply to
Elmo

Interestingly, the only time the cap failed was when they heat treated the coke bottle beforehand, as shown in in these tests:

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Interestingly, in general, the larger the bottle, the lower the burst pressure.

For example, while the standard 2 liter coke bottle with label burst at 168 psi, the standard 1.25 liter coke bottle burst at 185 psi.

Also interesting was the more gas (less liquid), the higher the burst pressure; for example, that same 1.25 liter coke bottle burst at 190 psi when it contained significant air.

In their last reported test, a 2 liter PET bottle failed at a lower psi than you'd expect (150 psi) after simulated use (held at 130 psi for 3 minutes). This test might indicate plastique fatigue occurs with repeated high pressurization.

So, I'd say Coke's report that all their bottles can handle 150 psi seems reasonable as the MOP (maximum operating pressure) for PETE bottles.

BTW, those numbers are all way higher than the "guesstimates" made here:

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Reply to
Elmo

Despite both Coke's statements and independent tests showing coke bottles exploding well almost at 200 psi, the mythbusters seem to intimate they explode at the much lower 150 psi pressure.

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So, I'm confused.

Reply to
Elmo

You are also an accident waiting to happen.

Reply to
snotty

Elmo wrote in news:hpjvad$35o$ snipped-for-privacy@tioat.net:

Explosion occurs at 150psi.

I think your confusion comes from some poor wording at that Wiki site.

This quote: "The Build Team also found that water cooler jugs, while able to launch higher at the standard air/water ratio for water bottle rockets, were weaker than standard soda bottles (which are designed to hold carbonated liquids), failing at around 60 psi (413 kPa) less than the soda bottles (90psi (600kPa) as opposed to 150psi (1000kPa))."

might read more clearly as: "The Build Team also found that water cooler jugs were able to launch higher at the standard air/water ratio for water bottle rockets. However, the jugs were weaker than standard soda bottles, failing at around 90 psi (600 kPa), much less than the soda bottles, which fail at 150psi (1000kPa)."

The intermixing of English and Metric also adds to the confusion of the Wiki page's wording.

Reply to
Tegger

Particularly on topic for me because I have an Air Horn on my bicycle:

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It uses what appears to be a slightly thicker version of a soda bottle. It is a very effective horn, in fact, a bit too loud. It sounds like a Hemi on helium but does get through those jogger's headphones.

Anyway, the bottle is usually fastened right below the crossbar, which is right below my, well, nuts. We're told to fill it to 100 psi. If there is one thing I don't want, it's that bottle exploding down there.

Note the cost of this item. The price "reduction" drops it below the free shipping ($25) level so it ends up costing more. Excuse me but I'll just pay full price and get it shipped for free.

Reply to
dgk

RTFM - it has a volume control.

Reply to
salty

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