Refilling 16 oz propane bottle off a 20# tank

MrWizard wrote:
everything is explosive, if put under the right pressure and/or impact

coal dust. the first diesel engines used powered coal dust
stationary use, did not catch on until somebody redesigned the engine to use petroleum

those exploding videos are fun to watch, but way out of contex
burning or shooting things to make them explode

So you say, they may be pertinent to someone who has no idea of how explosive it can be and has no business fooling around with cylinders of unknown age and questionable quality. Pretty disappointing coming from a moderator who should understand the importance of safety in enjoying a pastime. Since I did not tell the OP they were going to blow themselves up or make wild claims about it being illegal or any other such nonsense your comments are pretty telling in that you have no concern for doing things safely. Not one word from you to the OP about making sure they understand how to do it correctly just that exploding 1 lb cylinders of LP videos are out of context. That's laughable

fla-gypsy wrote:
You should be aware of the explosive potential of 1 lb of LP under pressure. The videos are out there.

also remember that new full bottles are sold inside stores, while used 20lb cylinders are not allowed back in stores when emptied, new ones only if empty.

I bought the fittings to make a nice setup to do this. I want to have several filled to use as needed on propane lantern, cookstove, etc. I bought a couple of brass w/gasket caps for the 16oz bottles, they are expensive, but I wanted the safety should I choose to carry them in front storage in trailer.

Jeez

If you fill a NO RUST bottle on a scale with exactly 16 oz of liquid, then check the fill port under water, What. Is. The. Big. Deal?

Of course there are some who can really do an excellent job screwing up a steel ball with a feather duster. But these folks are out of line when loudly crying Wolf that folks who know what they're doing are Dangerous.

The object should be learning how to do things correctly therefore safely.

fla-gypsy wrote:
You should be aware of the explosive potential of 1 lb of LP under pressure. The videos are out there.

You should be aware that the explosive potential of a 20 lbs cylinder under pressure is about 20 times greater than that of a 1 lbs cylinder.

MEXICOWANDERER wrote:
Jeez

If you fill a NO RUST bottle on a scale with exactly 16 oz of liquid, then check the fill port under water, What. Is. The. Big. Deal?

Of course there are some who can really do an excellent job screwing up a steel ball with a feather duster. But these folks are out of line when loudly crying Wolf that folks who know what they're doing are Dangerous.

The object should be learning how to do things correctly therefore safely.

I believe that was my point including knowing what can happen if it goes wrong before the "do anything no matter what crowd" jumped in concerning a simple warning to the OP!

nickthehunter wrote:

fla-gypsy wrote:
You should be aware of the explosive potential of 1 lb of LP under pressure. The videos are out there.

You should be aware that the explosive potential of a 20 lbs cylinder under pressure is about 20 times greater than that of a 1 lbs cylinder.

And a 30lb cylinder etc. etc. This I know, but the OP seemed very unsure of how the process works for refilling a cylinder designed to not be refilled. I'm in no position to tell anyone not to do something unless it is something I have expert knowledge of. I just wanted the OP to understand what could happen. These are key to reducing risk and avoiding hazards both of which are pillars of good safety practices which I am an expert on. Any other safety professionals want to chime in?

red31 wrote:
also remember that new full bottles are sold inside stores, while used 20lb cylinders are not allowed back in stores when emptied, new ones only if empty.

Good point.

It may be more dangerous filling the darn things than where they're stored. As long as you're saving money that's all that matters.

fla-gypsy wrote:

nickthehunter wrote:

fla-gypsy wrote:
You should be aware of the explosive potential of 1 lb of LP under pressure. The videos are out there.

You should be aware that the explosive potential of a 20 lbs cylinder under pressure is about 20 times greater than that of a 1 lbs cylinder.

And a 30lb cylinder etc. etc. This I know, but the OP seemed very unsure of how the process works for refilling a cylinder designed to not be refilled. I'm in no position to tell anyone not to do something unless it is something I have expert knowledge of. I just wanted the OP to understand what could happen. These are key to reducing risk and avoiding hazards both of which are pillars of good safety practices which I am an expert on. Any other safety professionals want to chime in?

The adapter came with no instructions. I understand the basic chemistry involved and Boyle's Temperature Pressure laws, such that cooling the cylinder to be filled gives a greater pressure differential, allowing it to be refilled in a more timely manner, as higher energy or an out doors tank being warmer to a frozen tank, and basic chemistry that heat seeks and dissipates to cold is what expedites the matter of the transfer to the cold bottle.

I am also aware of the risks of propane being combustible, doing it outside, wearing gloves so my hands don't freeze in case of a leak, etc, etc, etc.

I put 20+ gallons of diesel in my fuel tank every fillup while trailering my TT. I put pretty close to 40# of propane in 2 tanks every fillup.

I respect the fact that I don't need to get 16 oz in the container, and that anything less is a good idea. I also get that once I fill the 16 oz tank, it will immediately go on the BBQ for cooking meat, thereby relieving any chance of there being nothing but liquid in the container, there will be some buffer air space that's non liquid to allow for the liquid to expand if it gets warmer in temperature.

I am certain that 4 or 5 minutes on high to burn off the fat on the SS grill and scrape it clean, and then 8 minutes a side for a NY steak should bleed off a fair amount of fuel. Now 45 minutes for a tri tip is a whole other matter, about almost a tanks worth, last time I tried it.

A few suggestions: Most folks are filling more than one 1 lb. cylinder at a time. That's kind of good since the process can be scheduled and located away from anything that could be harmed.

All of the typical processes mentioned previously are valid, cold 1lb cylinder, invert 20 lb cylinder, etc.. Yes, a bucket of water will monitor seal integrity and heat the cylinder/contents so win-win. Coleman fuel cylinders develop the most seal leaks of any small ones we've filled. Bernzomatic is usually best, IIRC.

I would bet a doughnut that the explosive energy of a 20 lb cylinder is more than 20X greater than a 1 lb cylinder. Construction is different for higher operating pressures and the explosive result of the gas igniting wouldn't be linear as to weight difference.

Someone told me that the propane tanker I was on had the explosive energy of 20 Hiroshima's. Didn't seem possible but 1/4 of a Hiroshima would be too much.:(