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| blind909 |
Posted: 08/03/2007 18:12 PM Post subject: Pressure rating for soda bottles |
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 Brigadier General

Joined: 02 Aug 2007 Posts: 853 1193.92 Spud Bux
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| Can someone give me the pressure rating of a plastic coke bottle, sorry im a bit of a noob. |
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| hi |
Posted: 08/03/2007 18:16 PM Post subject: |
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 Major General

Joined: 01 Feb 2007 Posts: 1632 1425.41 Spud Bux
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its not rated. its made to hold soda and not much else.
some people say they are good to about 120 psi. im sure it will hold it, but i really dont tust it and i personally dont think it is smart.
the way i see it is that plumming parts are cheap and a foot of pvc costs the same for a bottle of coke. |
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| Insomniac |
Posted: 08/03/2007 18:19 PM Post subject: |
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 Major General

Joined: 18 Dec 2006 Posts: 1296 49.78 Spud Bux
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| Soda bottles don't have a pressure rating, but I have tested some to 100psi, so it should be pretty safe for 60-80psi. Just remember to ALWAYS use bottles that held a fizzy drink (water bottles are bad). Also, the coca cola branded bottles tend to be thicker than the other ones I've seen. It's a good idea to test any bottle before you use it. Just fill it to the brim with water and pressurise, that way, if it bursts, the amount of stored energy will be small. And welcome to Spudfiles! |
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| blind909 |
Posted: 08/03/2007 18:20 PM Post subject: |
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 Brigadier General

Joined: 02 Aug 2007 Posts: 853 1193.92 Spud Bux
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| I am only filling it too 35 psi, it is alot lighter than pvc and is for a bbmg, so I should be ok, and thanks. |
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| SpudBlaster15 |
Posted: 08/03/2007 18:51 PM Post subject: |
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 Major General

Joined: 18 Oct 2006 Posts: 2401 1549.30 Spud Bux
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| Plastic drink bottles are usually pressurized to ~50-60psi before sale, so you should be fine to pressurize them to 35psi. |
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| blind909 |
Posted: 08/03/2007 19:29 PM Post subject: |
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 Brigadier General

Joined: 02 Aug 2007 Posts: 853 1193.92 Spud Bux
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| Thanks man, so I will be fine. |
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| mtronic |
Posted: 08/03/2007 21:18 PM Post subject: |
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 1st Lieutenant

Joined: 23 Jun 2007 Posts: 292 472.90 Spud Bux
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| I have taken a 2ltr coke bottle to 140psi but I wouldn't go any higher than that and wouldn't do it often. |
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| sandman |
Posted: 08/03/2007 21:33 PM Post subject: |
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Colonel

Joined: 15 Mar 2007 Posts: 676 945.79 Spud Bux
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| mythbusters exploded one at 150 so you are very safe at 35 |
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| mopherman |
Posted: 08/03/2007 21:38 PM Post subject: |
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 Brigadier General

Joined: 03 Feb 2007 Posts: 796 847.70 Spud Bux
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| sandman wrote: | | mythbusters exploded one at 150 so you are very safe at 35 |
mythbusters is a cool show, but dont use them as a source of info for spudguns. remember the giant ball valve cannon? inconsistant opening times and a horrible cb ratio made it a horrible cannon for testing.
back on topic: yeah its safe up to about 50 psi. |
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| 666lucky693 |
Posted: 08/03/2007 21:43 PM Post subject: |
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 Master Sergeant

Joined: 03 Dec 2006 Posts: 169 0.96 Spud Bux
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| ive taken one up to 145 thats about all that i would trust it to but they are fine i made many cannons with them it and they were fine |
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| dauphinoise potato |
Posted: 08/04/2007 6:40 AM Post subject: |
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 Staff Sergeant

Joined: 15 Jul 2007 Posts: 105 154.72 Spud Bux
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I got bored one day and took a evian water bottle to over 120psi, very loud bang  |
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| jimmy101 |
Posted: 08/04/2007 13:38 PM Post subject: |
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Lieutenant General

Joined: 28 Mar 2007 Posts: 2990 12426.78 Spud Bux
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| Plastic soda bottles for carbonated beverages most definitely are pressure rated. Get off you behind and do some googling. |
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| joannaardway |
Posted: 08/05/2007 6:22 AM Post subject: |
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 Brigadier General

Joined: 09 Oct 2006 Posts: 954 115.90 Spud Bux
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I wouldn't say that drinks bottles are "pressure rated" - I'd say pressure tested.
Being technical, a rating is when a manufacturer has certified the product for use at a pressure. Coke don't naturally certify their bottles (that's asking for trouble), but can be coerced into giving information about what they've been tested to.
I'd personally be confident with a tough, non-collapsable (the evian bottles are specifically designed to be crushed to recycle) bottle at up to 100-120 psi.
They share the quality of ABS that should they fail, they tend to tear rather than shatter, which means that should anything go wrong, you'll just be short of hearing for a short while - unless you're holding your head to it. |
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| jackssmirkingrevenge |
Posted: 08/05/2007 6:35 AM Post subject: |
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 aspiring machinist

Joined: 15 Mar 2007 Posts: 21750 40551.64 Spud Bux
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| joannaardway wrote: | | Being technical, a rating is when a manufacturer has certified the product for use at a pressure. Coke don't naturally certify their bottles (that's asking for trouble), but can be coerced into giving information about what they've been tested to. |
Having worked in the quality control lab of a well known beverage manufacturer, I can vouch for the pressure testing of PET bottles used for non-carbonated beverages (Iced Tea etc.) - naturally not all blown bottles are tested, a sample from each mould is taken at regular intervals and the bottle is tested to failure in a sealed pressure-tester.
Typical failure figures are just over 300 psi for 0.5 litre bottles and just under 200 psi for 1.5 litre bottles. Bottles designed for non-carbonated beverages such as bottled water fail at much lower pressures, typically below 100 psi. As a general rule, the smaller the bottle, the higher the pressure it can take.
Note also that quality varies from bottle to bottle - look at the little teat at the base of the bottle, if it appears too thick then it's a likely point of failure. |
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| jimmy101 |
Posted: 08/05/2007 16:29 PM Post subject: |
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Lieutenant General

Joined: 28 Mar 2007 Posts: 2990 12426.78 Spud Bux
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I knew there was somebody on the board that new about pressure testing of plastic bottles.
There is really very little difference between pressure testing and pressure rating unless you're being picky.
"Pressure testing" is the act of collecting data. "Pressure rating" is what you get after the testing data has been examined by statisticians and lawyers. "If 99.9% of the bottle don't fail under conditions X, the cost of a failure is $Y, we sell 4 zillion bottles a year, therefore our liability will be ..."
I'm sure that the Coca Cola™ company tells their bottle manufacturer that the nominal pressure at normal temperature is such and such. But, the bottle must not fail at the pressure it'll have at 150 F, or something like that. The inside of a car will easily hit 150 F on a hot sunny day. I'm also sure there is a many page document that specifies in gory detail the failure statistics at various pressures and temperatures.
Naturally, bottlers are not interested in telling anybody what the actual testing data is or what the derived ratings are. Why should they? It would just be ammo for liability lawyers. |
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