Refilling small propane cylinders

Course we are! We're just harder to light.

Reply to
Andy Dingley
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I found this cut away image (along with a few others) of an OPD device:

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I don't know if they all look the same or not, but the ones I checked did.

It looks like liquid would come out okay if the tank wasn't almost empty. Hard to say how the float might act at that point...

Reply to
Leon Fisk

I see your logic, but remember it cuts off the gas if dumped over. Have you seen the funny/stupid add on TV with the women at the window playing with it - as the dog, man and Barbie blows up... that's why we get OPD.

I like one thing - I don't have to get a wrench from the shop to change a bottle now. Just reach down and turn like my mind wants - right hand outside screw. Not the left hand internal with a hex nut.

I think there are internal elements - like on wet/dry vacs - with a floating ball... Without one in a hand, it is hard to say for certain. There was a web page that showed some of this or how it worked.

Martin Martin Eastburn @ home at Lions' Lair with our computer lionslair at consolidated dot net NRA LOH & Endowment Member NRA Second Amendment Task Force Charter Founder

Eric R Snow wrote:

Reply to
Martin H. Eastburn

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Perhaps the early ones cut off the gas but now the new ones don't ? Hum... :

Q: Roofers and other commercial customers are trying to use OPD equipped tanks on torch applications and they are not getting an adequate flow through the valve. What can we do about this?

A: Some of the early OPD valves had an insufficient flow capacity for certain types of service such as high-pressure torch applications. Market competition has resulted in OPD's becoming available that have significantly greater rates of flow.

©NPGA 2002

Martin Eastburn @ home at Lions' Lair with our computer lionslair at consolidated dot net NRA LOH & Endowment Member NRA Second Amendment Task Force Charter Founder

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Reply to
Martin H. Eastburn

Reply to
David Seidel

I saw 'em in two and use 'em as drinking cups. The wife has a full set now. Thsoe made from the 20# ers are a bit hard to hold, though.

Bob Swinney

Reply to
Robert Swinney

Hey, folks. I refill the small 1 lb coleman cylinders all the time. Harbor freight sells an adapter you screw onto your warm (60 - 70 F)

20lb cylinder. Put an EMPTY 1lb into the freezer overnight. Screw the bottle on the adapter connected to the 20lb. Flip this assembly upside down THEN open the valve for 1 minute. Close valve, THEN put assembly right side up. Remove 1 lb. You will get a poof of gas as the safety tube in the 20lb purges. Be sure to remove the adapter for storage to keep the 20lb safe. This fills them to the perfect level about ten times. Then you can refill the 20lb. I believe messing with the valve or filling 2 or 3 times is STUPID!!! I have done it this way for years. If the 1lb shows ANY sign of leakage at the valve I simply toss it and use a new one. Hey, they are pretty cheap and not worth getting killed over.
Reply to
peter

I fill CO2 tanks for paintball the same way. Sometimes I skip the freezer part, and just put a couple ounces of CO2 in the small tank, then let it vent. That cools the tank very well. Of course, I wouldn't recommend that for propane. :)

You really should be using scales when you fill your tanks. It is quite possible to overfill them the way you're doing it. Remember, as your tank warms up, the pressure inside increases.

Reply to
Dave Lyon

its about impossible to overfill a propane disposable since the adapeter and bbq tank cause the little disposable to sit sideways

on my best fill o've only ever been able to get 12 oz back inside

i use a 2 pound scale an empty disposable weighs 14.5(coleman brand with plastic bottom that always falls off) at the fill if i get 26 oz i'm happy its enough to keep my lantern working all night

some times it doesnt seal off when removing and has a little hiss so i take a nail and just poke the valve until it is seated(kind of a tapping motion)

having them in the freezer overnight makes the seals not seal so good so i just fridge em for 20 minutes

and make sure you leave the bbq tank in the sun to heat it up

Reply to
2000man

propane, co2, and nitrous all have low boiling points, and all are pretty similar.

from filling nitrous bottles, i have figured otu a few things. saying you can't fill a propane bottle full because it is on itsside is incorrect. we are NOT talking about water and air where it flows liquid until it can' t fill.

the whole trick is temperature. the propane flows from high pressure to low pressure. there are only two ways to create a pressure differential. Temperature, and a pump. with either, you can move propane from the high pressure side to teh low pressure side, until pressures are equal, no matter how much head spade there is.

propane in gasseous state takes a lot longer then propane in liquid state to move through a hose. Further, if you are moving the prpoane in gaseous state, you must convert the propane in hte sending tank from liquid to gaseous, which takes up a lot of heat.

Therefore, the sending tank cools off in a big hurry. Likewise, the tank receiving gas must convert it to liquid, which warms the receiving tank up.

if you overfill the little tank, and the over pressure valve fails, a VERY VERY large explosion can occur. It only takes a little head space, but it does take some head space.

For grins, and a feeble example, stuff some dry ice into a plastic pop bottle, screw on the lid, adn throw it out in the sun for 20 minutes. do not stand very close. it is pretty impressive to see what happens when a container blows up.

i used to fill nitrous botttle FULL, then crack the top for a second wasting some liquid nitrous. it guaranteed some head space.

Reply to
Doug

well i've filled close to 50 little tanks and havent been able to get more than 12 oz in a 16oz container

a pop bottle can only handle 90 psi

in my locale they call dry ice in a glass bottle a"infernal device"

anybody know the maximum pressure dry ice can make in a container assume ambiant temp 80 farenheit

Reply to
2000man

When I was a kid (about 30 years ago) I helped my dad with wheat harvest. Our 2 combines ran on propane. The tank on the combine was 8 to 10 feet above ground. Our supply tank was about 4 feet above ground. We'd connect the two tanks and open the bleeder valve, venting vapor into the air. Liquid propane moved up to fill the tank on the combine. Did this every day for the week or two of harvest.

Reply to
Les

yea but your ground tank had a wet leg

a bbq tank doesnt so you have to turn it upsidedown to get liquid propane

also it wastes a bit of propane when you vent it is not a signifigant percentage when filling large tanks

Reply to
2000man

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