Filling 20lb & 30lb propane tanks

Need some advice from somebody that has already done this. I have a "wet tap" on my 500 gallon propane tank. I am trying to transfer propane to smaller bottles and have questions.
Here's what I do. Connect hose to propane bottle. Open top of bottle valve. Crack open bleeder screw and set for light 'hiss'. Open valve at end of hose, and then slowly open valve at the top of the storage tank.
Problems: While my bottles are fairly new, I am only able to completely fill one of the 20lb. bottles (fill until liquid escapes from the relief weld. This took exactly 8 minutes. Bottle weighed 18lbs. at start (empty) and 35 lbs. finished. Not quite full (38 lbs.) but close.
The other three bottles (one 20lb and two 30 lb) don't seem to want to fill. Left them each on for 25 to 30 minutes. Each of the three took about 8 lbs., at which point I gave up.
What is everyone else's experience? How long does it take? Am I losing more propane out the relief valve (30 minutes) than the two gallons I am putting in?
DATA: 500 gallon propane tank 80% full. Bottles about 1 foot lower in elevation than tank. Big tank in full sunshine, bottles kept cool in shop. Bottles all newer type with triangular handle. All bottles 'bounced' lightly on the concrete to make sure internal float valve not stuck.
Would the older style bottles (no float valve) fill easier. Kind of thinking that the float valves could be a restriction that becomes an issue when you are trying to gravity/pressure feed as opposed to having it pumped as at the service stations.
All thoughts appreciated.
Ivan Vegvary
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Ivan Vegvary wrote:

Try venting the empty down to close to ambient air pressure before you start the fill . This will let the inrush of propane boil and chill , which will drop the vapor pressure in the empty/receiving bottle lower than the vapor pressure in the big tank . Once the fill starts you can close the vent most of the way . Propane is an excellent refrigerant gas ...
--
Snag
Learning keeps
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Hi Snag, Excellent suggestion, I will give it a try. Unfortunately the 30lb tanks were already partially filled (1/4 way) so I would be losing a lot of product if I vent.
Ivan Vegvary
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 6/18/2011 8:28 PM, Ivan Vegvary wrote:

already partially filled (1/4 way) so I would be losing a lot of product if I vent.

Snag's idea will work in reverse also, hook the 30# tanks back up & warm them up & they will empty back into the big tank, then you can just vent the remaining gas- assuming no check valves in the setup.
MikeB
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
BQ340 wrote:

I'm going on personal experience , we did our camper tanks from Dad's 200 gallon tank . Also did torch bottles , sure beat the prices at the hardware store !
--
Snag
Learning keeps
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Ivan Vegvary wrote:

Use what's in there before you try again ...
--
Snag
Learning keeps
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I've had problems with some of the new-style fill valves with gravity feeding, none with the old POL valves. The propane services fill by weight, not volume, so you're checking things correctly. You're doing things the way I do. I like more than a foot of drop, but with a fixed tank you're stuck unless you dig a hole. When I made up my fill hose, I added a ball valve immediately before the tank fitting for the cylinder being filled. Leaves the hose filled with liquid when I break the connection.
With this style filling you're depending on the bleed valve to provide enough pressure drop to feed liquid in but not enough to allow it all to boil off. With small cylinders, I've cooled them off before filling, then gravity did the job, if slowly, didn't crack the bleeder at all.
Stan
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Sun, 19 Jun 2011 10:24:48 -0700 (PDT), snipped-for-privacy@prolynx.com, snipped-for-privacy@prolynx.com wrote:

IME, MOST propane services fill by volume and you pay by the gallon. Take an RV or travel trailer around the country to verify for yourself. Last place I got the 20 lber filled for the grill was in Farmington, NM. The guy only put 4.5 gallons in. Didn't weigh, didn't wait for it to "overfill" as some do, just 4.5 gallons. Period. Same guy filled the empty 30 lb'er with 7 gallons.
Cortez, CO. Same. Gallons. Show Low, AZ. Gallons. Cass Lake, MN. Gallons. Portsmouth, NH. Gallons.
Now that I think about it, I know I've bought propane by weight, but I can't think... ah, Strafford, NH. Pounds. At least one place. And they didn't weight before and after to see how many lbs. you got. They stuck your bottle on the scale, started filling, and when the preset weight was reached, they stopped. If you had a half-bottle to begin with, you paid the same as if you had one that was at 0 psig.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Fri, 24 Jun 2011 02:19:41 -0700, Gunner Asch wrote:

Ferrell brand at a campground today. $3.50 a gallon. Not too bad a markup, considering they claimed they'd come by your site, pick up your bottle(s), fill, and return. (Turned out not to be the case in this instance... I had to self-schlep. Oh well.)
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
"Steve Ackman"
message

The corner store here in Twin Lakes Mi (49965) refills bottles by weight and RV's by volume. All bottles have a tare weight stamped into it, add 5.5 lbs for the filling nozzle and hose, add the containers size and set the balance scale to this number. Say a 100 lb'er is 75 empty, plus 5.5 for hookup plus 100 for propane makes 180.5 lbs and the scale is set to that. When the beam tips the bottle is full to its design content. If the bottle is partially filled the remaining content is easily calculated on the scale before hookup. You pay only for what it takes to fill it. Same for RV's. You pay by the gallon for what it takes to fill it. Bottles are sold by weight and RV's by gallons. They run an honest place there, eih? And that leads to happily returning customers to buy other stuff! Like they say, you're far better off in the long run to make a little money off a lot of people than you are trying to make a lot of money off a few..... You'll have a lot more fun ! ;>)}
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Mon, 11 Jul 2011 17:14:51 -0700, Steve Ackman

Around here (Ontario Canada) any "portable" tank is filled by weight and charged a flat rate. Highway Robbery type prices.
Propane Motor Fuel (same stuff) is sold by the liter into "mounted" tanks.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Are you going to a propane service or to a filling station? I've used filling stations a couple of times, didn't like the way they did it, I now use either a propane service or a tool rental place, both fill tanks by weight. I only pay for the actual fill weight, not the difference between empty tare weight and filled weight. Haven't had to fill the big tank for several years, don't know current propane price.
Stan
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
message wrote:

Then they are ripping you off! Start the bitching!
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Tue, 12 Jul 2011 18:24:01 -0400, "Phil Kangas"

If you are buying "road propane" - motor vehicle fuel, the price is not bad. In SOME states/provinces there is no road tax on Propane, but often you still pay more for propane that is guaranteed to be of a certain composition (can't rmrmber the designation - but it has to do with sulpher levels etc) even though it comes out of the same tank as "bottle gas" for Bar-B-Qs etc.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

That is fairly expensive, I run my Patrol on LPG which is currently at 65c / litre which is about $2.45 per USG, or about $2.60 US. Not so long ago that would have been about $4 US but your currency is now about 4 floors below ground level.
At service stations, exchange 9kg gas cylinders are about $25 - a ripoff, although, when considering the time to fill them about $18 is reasonable. I fill my 9kg for about $13.70 at the pump (21 litres).
    Alan
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

It is definitely done differently from place to place.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here. All logos and trade names are the property of their respective owners.