Using Charles' Law of Gases:
V1/T1 =V2/T2
and making the following assumptions:
1. It works as an ideal gas.
2. At boiling the liquid phase still occupies ~1000mL of the container.
3. Pressure is constant at Standard Atmospheric Pressure (760 torr).
4. The bag will rupture at anything above atmospheric pressure.
5. The initial volume of gas vapor is 0.
Then:
V2=(T2V1)/T1
where
V1=0
T1=10C=283K (add 273 to 10)
T2=100C=373K (add 273 to 100)
V2=600mL (1600 total - 1000 liquid water)

So:
V2 = (373K*600mL)/283K = 790.8mL and the bag ruptures.

Now, lets figure out what sort of pressures the bag needs to hold this water/vapor.

Boyle's Law states P1V1=P2V2
In our case:
P1=760 torr
V1=790.8mL
V2=600mL
then:
P2 = (P1V1)/V2 = (760torr*790.8mL)/600mL = 1001.7 torr = 19.4 psi

So the bag would need to withstand at least 20psi to prevent rupture during this process. A good engineer would want a safety factor of at least 40% so figure a necessary rupture strength of 25psi.

Remember, this makes some assumptions about the property of water vapor. I did these calculations before my morning caffeine dosage so don't trust your life to them.

-Blast

Clear,not silvered bags. But they're stored in a Stainless Steel locker. If you draw any vacuum, you need to freeze the water first or it absolutely will suck into the mechanism. I don't worry about drawing a vacuum. I just seal. Honestly, since the bags aren't pre-sterilized and since the vacuum won't really remove ALL of the air anyway, I don't worry about the air left in the bag when I seal it.

It sounds like you've thought this out pretty well. I think you might be on to something.

The only reason I brought up purity concerns is because I have noticed a difference in stored bottled water as opposed to stored drinking water. I've drank 1-2 year old bottle water with absolutely no indication of old age, where as after a few months, regular drinking water stored in a Nalgene bottle starts to smell a little funny. I'm sure it's still drinkable, I just notice a smell, so I assume that there is probably somethign in the water. I admit that I don't go through the precautions when filling up the bottle, it's just a straight fill from the water cooler, so that could be the cause of it.

So a drop or two of bleach or iodine sounds like a must for what I have in mind.

You're math checks out; I knew it was something simple but I couldn't remember anything but PV=nRT, and I couldn't remember R's values. I'll accept your properties of water vapor, gas laws almost earned me a D in chem.

But don't the market these things as giving you the ability to seal and freeze a meal, then heat it in boiling water?

*sighs* I guess if the IRS decides to give me some money back, I need to break down and determine this by experiment.

ironraven - I guess what you're really trying to do is retort-package your own water. By the way, I suppose it is possible to home can your own water, if you wanted to (glass jars?!?)

I would get some food grade plastic bags, possibly with an aluminum "oxygen barrier" layer, fill partway with tap water leaving some space, squeeze out all the air and then heat seal. Boil in a water bath or even a pressure cooker. Now everything inside is dead.

Now, how do you set an expiration date?

I hadn't realized it, buy yeah, I guess that is what I'm trying to do. So when I get a sealer, I should try this, then compare the price per liter to buying Aquablox which are a lot more rugged.