Pressure Cooking

[GordMay]

Originally Posted by Blue Stocking

I very rarely (sic: almost always) disagree with Brent, but his earlier statement that water does not expand when released from heat and pressure is incorrect and dangerous.
Water, when converting to steam expands 1700 to 1.
It is the basic principle behind water being used in firefighting. Atomized spray from the hose nozzles converts to steam, and absorbs the heat.
As a 20yr service, fire officer, and instructor, I taught this subject in depth.
Its also how steam engines operate.

Indeed.

[Brent Swain]

Originally Posted by Blue Stocking

I very rarely disagree with Brent, but his earlier statement that water does not expand when released from heat and pressure is incorrect and dangerous.
Water, when converting to steam expands 1700 to 1.
It is the basic principle behind water being used in firefighting. Atomized spray from the hose nozzles converts to steam, and absorbs the heat.
As a 20yr service, fire officer, and instructor, I taught this subject in depth.
Its also how steam engines operate.

I was referring to cold water for the test, not boiling water. Go back and read my post, thoroughly, before responding.
My father, a steam engineer all his life, said you can be standing next to a 3000 PSI pipe when it bursts, and be in absolutely no danger, as long as it is filled with water. A steam filled pipe will blow you to bits. Steam expands , cold water doesn't.

[Bergovoy]

Originally Posted by Brent Swain

...you can be standing next to a 3000 PSI pipe when it bursts, and be in absolutely no danger, as long as it is filled with water.

i gotta question this response as well...

If a steel pipe BLOWS/BURSTS. there will be a shock wave, from the air, AT LEAST.. then there will be schrapnel...from the metal pipe failing...

[Minggat]

Originally Posted by Bergovoy

i gotta question this response as well...

If a steel pipe BLOWS/BURSTS. there will be a shock wave, from the air, AT LEAST.. then there will be schrapnel...from the metal pipe failing...

Some of the best thread drift money can buy, but it's free.

You guys are splitting hairs. But Brent has it right. NO compressed air in the pipe to expand and be a driving force, and total INSTANT release will be messy and wet. That's all.

Water, HEATED into it's vapor form is expanded 17,000 times. Brent was talking about cold water.

It's not so much the pressure that expands metal. It's the heat. That's why running a stuck metal lid under hot water will make it easier to remove from the jar.

My favorite. "mom and grandma did it all their lives without a single loss of life".
Here in Asia you see people do the most unsafe things. It's really scary. But the logic is, "I didn't die yesterday, so it's OK to do again today". When they do die, it was "Gods Will".

Lets talk abnout food some more.

[DeepFrz]

I don't often agree with Brent but I think he was talking about pressurizing the vessel, not with steam but with air.

[Bergovoy]

yea, i understand the 'method' of pressuring... it was the 'controled' release or the bursting of the pipe, in an uncontrolled release, i.e. higher pressure then rated.. whether it is from expansion of whatever volume is inthere or from an additional volume is what i am talking/thinking about...

pressure is pressure.. if it is too much, it is too much and things will be bad... if it is just a measure of pressure and or where it comes from that is different...

sorry.. like i said before somewhere, I am literal... prolly too much in this case me thinks...

[JanetGroene]

To a mere slip of a lass like myself, the weight of the cooker and contents is a controlling factor. My 6-quart is a bit much to handle.

Originally Posted by Trox

I was looking at them the other day. Will the 4 quart meet most your needs? They looked small to me.

[zeehag]

i bought a 4 qt in gulf--didnt get a chance to use the cute lil thing-- want to find another at the same price-- i thinks it was presto, which work just fine for decades...... mebbe i wont cook so much at one time in a smaller pot..LOL
me with inabilities to carry heavy items great distances find holding dampot of 6 qt with both hands and loud noises to get help works well.....

[Trox]

Originally Posted by JanetGroene

To a mere slip of a lass like myself, the weight of the cooker and contents is a controlling factor. My 6-quart is a bit much to handle.

Thanks for the reply, Janet.

[Minggat]

Originally Posted by Minggat

Some of the best thread drift money can buy, but it's free.

You guys are splitting hairs. But Brent has it right. NO compressed air in the pipe to expand and be a driving force, and total INSTANT release will be messy and wet. That's all.


Lets talk abnout food some more.

OK, I'm quoteing myself here.

I hate when people make statements like I made here. So....
I afraid that I may be turning into a grumpy old man here.

Think of the pressure in the pipe with no air, as a sealed jar in the freezer full of water. As the water freezes, the jar burst without flying glass. Now think of a can of soda in the freezer. When the soda freezes and ruptures the can, the gas in the can might be a driveing force to... spew a mess. The problem with my analogy is, the mess is frozed stiff, so it doesn't spew very far.

Warning. I'm still a grumpy old man. I seem unable to reverse the process. I think it has to do with being young but my defective mirror only displays an old version of me.

[SurferShane]

Originally Posted by Bergovoy

im guessng you ahve never seen a tire blow up?

PSI = pounds per square inches.. now, take 15 pounds times the number of square inches mulitiplied by 15, (assuming that is the correct pressure), and include the po0tential/stored energy by the expansion / tensile strength of the metal and seals and BAM BAM KABOOM...

you will not want to be anywhere near there, not to mention just the concussion and schrapnel, but the hot material inside will be sprayed over a distance of about 10' at least...

just sayin'

Lot more safety valves and design thought put into modern pressure cookers?

[SurferShane]

A smaller cooker is on the list for me as an compliment to the med\large one I already use. Hopefully stainless steel with dual handles like the one I posted a link too earlier in the thread. Just not interested in going back to normal pots on the boat.

[Bergovoy]

Originally Posted by SurferShane

Lot more safety valves and design thought put into modern pressure cookers?

i have covered that, and indicated that the likelyhood of that happening is rare, to non existant depending on how new and what safety devices are encorporated...

[Bergovoy]

Originally Posted by Minggat

OK, I'm quoteing myself here.

I hate when people make statements like I made here. So....
I afraid that I may be turning into a grumpy old man here.

Think of the pressure in the pipe with no air, as a sealed jar in the freezer full of water. As the water freezes, the jar burst without flying glass. Now think of a can of soda in the freezer. When the soda freezes and ruptures the can, the gas in the can might be a driveing force to... spew a mess. The problem with my analogy is, the mess is frozed stiff, so it doesn't spew very far.

Warning. I'm still a grumpy old man. I seem unable to reverse the process. I think it has to do with being young but my defective mirror only displays an old version of me.

umm, confused, but not sure why...

when i forget to take my soda out of the freezer the spray is all over.. it would spreay across the kitchen if there werent freezer walls... you can tell by the splatter...

Im guessing that the gas isnt frozen and when the can ruptures, it starts off with small hole in teh can and the spray comes out faster and further, and as the failure in the can increases in doesnt spray as far, and the crack in the can continues to open until the pressure no longer pulls on it and it can escape without restriction...

a bit more slower then a tire erupting, but still 'uncontrolled'..

[SurferShane]

Originally Posted by Bergovoy

i have covered that, and indicated that the likelyhood of that happening is rare, to non existant depending on how new and what safety devices are encorporated...

Still glad I got my med/large cooker free off the street cause a neighbours misses freaked it might kill half the family!