propane weights and opd

ok, i posted this in my thread as well, but for those not following it i have this question about a sign i saw at the local stop-n-rob.....
am i correct thinking a 20lb propane tank should actually hold 18lbs with opd(overflow protection device)
or should it still be holding 20lbs with 20% space for expansion ??
 
either way, i think its kind of sad that companies are actually bragging about the fact they under fill them
 
well, wait, its late, 20lbs filled to 80% would only be 16lbs...... so what gives ??? are they under or over filling ???

or will a 20lb tank actually hold 24lbs if filled 100%.......... im lost now

The way I have read, a 20lb tank holds 20lbs, when I get mine filled they set the scale to 40lbs, 20lbs gas about 18lbs for the tank and about 2lbs for the nozzle hooked to the tank to fill it, so I am getting about 20lbs of gas.
 
All the exchange one around here say they only have 17 lbs of gas in them.

From www.propane101.com ...

Cylinders Filled By Weight

Following the visual exterior bottle inspection, the bottle filler will look for two other things prior to hooking up the fill hose with the cylinder on the scale. These two things are the water capacity and tare weight. The water capacity is how much water the propane bottle will hold in pounds. The "WC" stamped on the bottle followed by a number such as "47.6" means the bottle will hold 47.6 pounds of water. The tare weight (empty weight) indicated by a "TW" is also followed by a number such as "18" meaning the bottle weighs 18 pounds when empty. The numbers here would likely be found on a five gallon propane bottle (also known as a 20 pound cylinder) used for a barbeque grill.
 
The bottle filling station will generally have a cylinder filling chart that converts water capacity (WC) to pounds of propane that the filler will refer to before filling the bottle. The chart will show that 47.6 pounds of water converts to 20 pounds of propane. In other words, a propane bottle that will hold 47.6 pounds of water will hold 20 pounds of propane. This indicates that the scale needs to be set a little over 38 pounds (20 lbs + 18 lbs = 38 lbs) to obtain the weight of the bottle when it reaches its allowable capacity.
After the scale is set and the hose end nozzle is hooked up to the cylinder, the attendant may open the bleeder valve, reset the meter and begin pumping propane into the bottle. The attendant will stop the pump once:

1. The bleeder valve starts to spew liquid
2. The scale indicates the cylinder has reached its legal filling capacity
3. The OPD valve stops the flow of propane into the cylinder (if equipped with an OPD valve)

Some companies will load your cylinder in your vehicle for you once the cylinder has been filled while some companies are not allowed to do this due to liability reasons. So don't be offended if you have to load your own cylinder. The bottle filling attendant is just following the rules.

Cylinders Filled By Bleeder Valve

Cylinders filled by fixed liquid level gauge, such as forklift cylinders are not required to be filled by weight. They are subject to visual inspections and recertification requirements like all cylinders but are not filled using a scale. Some companies may use a scale but the standard practice is to use the fixed liquid level gauge (bleeder valve). Once the hose end nozzle is hooked up to the cylinder and the pump is turned on, the bottle filler will wait for liquid to spew out and turn off the pump. The bleeder valve will be closed and the hose will be disconnected. The bleeder valve is the indicator letting the attendant know when the cylinder is full. He's not inadvertently letting propane out of your cylinder but rather following the rules and abiding by the law governing cylinder filling.

 
I get 5 gallons (4.7 actually) of propane put in my empty 20# tank. It's normally 4.7 gallons for a slap-dad empty tank. Many tank exchangers are only filling the tanks to 15#. Blue Rhino has it on their website. To fill to 17lbs is still "underweight" for a 20# BBQ tank. I prefer to refill my tank (and pay by the gallon) rather than swap. we only swap when we need to replace the tank or are unable to refill.
 
On edit...
4.22lbs of propane per gallon of propane for those who want to do the math
 
4.22 X 4.7 = 19.834  pretty darn close to 20 gallons

lornaschinske


I get 5 gallons (4.7 actually) of propane put in my empty 20# tank. It's normally 5 gallons for a slap-dad empty tank. Many tank exchangers are only filling the tanks to 15#. Blue Rhino has it on their website. To fill to 17lbs is still "underweight" for a 20# BBQ tank. I prefer to refill my tank (and pay by the gallon) rather than swap. we only swap when we need to replace the tank or are unable to refill.

 
I will never swap mine until the tanks need testing, we always fill to start the smoker with a full tank.

KurtSara

I will never swap mine until the tanks need testing, we always fill to start the smoker with a full tank.

 
You must be lucky enough to have fill stations that are open on the weekends and staffed by people who know how to fill a tank. Our last tank that we had filled  was completely empty. Moron put 3 gallons in it and said it was full. In Socorro, all the fill station (all two of them) closed down on Friday between Noon and 3PM. If it was a holiday weekend, they may or may not open back up on Monday morning. I used to be one of those folks who NEVER swapped a tank. I had the luxury of sitting in my yard and cleaning up a tank then repainting it. When you live in campgrounds, there are many things you no longer do. Upside is I no longer have to mow the grass. Thank God I'm "houseless"!!!!

Here is a good site to read on topic, and there are over 150 post on this topic. Here are two on point.
 
(16) Ed says:
Blue Rhino is a complete ripoff. For years they were filling their tanks to about 18lbs and few noticed. They’ve since decided to get greedier by filling the tanks to only about 15lbs. When caught their only response was to say it was for safety reasons since overfilling a tank can be dangerous. This is a total lie. A 20lb propane tank for example, is designed to hold 20lbs (4.72 gallons)of propane which when filled will provide a 20% vapor area. Additionally, the valves in use today will not allow the tank to be overfilled. If someone has an older tank, any reputable dealer will not fill the tank. Apparently Amerigas is participating in this same ripoff. Did I mention that these two outfits also charge much more than if you were to refill at a local dealer? Fore example: The local Home Depot sells Blue Rhino exchanges for $22.99 for a 3/4 filled tank when I can go to a local dealer and get the full 20lb for about $15.
 
(24) Dale M. says: I may have a little different view on propane tank refilling. We’ve refilled ours for years off of our own 500 & 1,000 gallon propane tanks using the same appartus used for refilling forklift and farm tractor tanks. Not practical or safe for most consumers but having also worked in the propane business I can say that your best value is almost always to have your own tank refilled to the Tare Weight + 20lbs or +30lbs, depending on the tank size of course and skip the whole tank exchange thing. Better yet, have two tanks on hand so you can run the one tank completely empty before refilling it as most refilling stations charge a flat rate no matter how empty [or not] your tank is.
Happy grilling!


http://bbq.about.com/b/20...-your-propane-tank.htm

A 20lb propane tank for example, is designed to hold 20lbs (4.72 gallons)of propane which when filled will provide a 20% vapor area. 
 
how in the hell do they get away with this ???
i was right in assuming they actually only ripping you off 13% less then the competitor.....
whats next.....the food industry going to go to a 3oz quarter pounder before cooking for "health" reasons ?????????
 
aarrrrgggghhhhhhhhhhhhhhh....... this is the big business bull**** that sends me over the edge !!!, and yes, if it lets me i spelled out BULL **** because thats exactly what it is !!

thays exactly why I get my tanks filled at a place that has a meter,(and uses it) and only charges for what goes in the tank...............

Same here.....I only pay for what is pumped.
 

When you do a tank swap, you are actually buying the tank.  When you refill a tank, you should be getting almost 5 gallons or you get it filled by the pound. The sign in the first post is for a SWAP.
 
Ever seen someone buy a new BBQ grill that comes with a new tank or just buys a new tank, then swaps their brand new tank for what is basically a USED semi full tank? The Lowes in Franklin NC did that all the time.  And these customers don't realize they just paid $15+ for a used tank of LP when they could have stopped 1 block over and filled their brand new tank with $10 of LP (those are old prices since I haven't been in Franklin since 2009). There is a good use for tank swaps and like I said, I have used them fairly often in the past 5 years. But I am a more informed consumer than many who use the same service. Like ice cream and many other products... the package stays the same size and the contents shrink. And no one realizes the price increase.

when i worked at home depot that was a standard thing..... i never understood why the manager was so happy to see someone buy a new grill, and then trade in the tank for a blue rhino one....
or better yet, if you went to home depot to buy a tank, to buy a BR one was 50 bucks, or....... you could go into the store, buy a HD tank(empty) for 25 bucks, and swap it for a BR tank from out front for 20 bucks...saving you 5 bucks....
now its all making sense, lol

and i agree..... although i have pondered having a way to tie in a 20lb tank for extended stays or emergencies, with the idea that i could stop at most any gas station and pick one up in a pinch, i have always planned on having my tanks filled at a propane filling station we have several larger companies that do it, and my main idea was to use the marina down by the river..... they have a filling station and weigh everything every time and you only pay for what they put in...
 
of course, the bulk tank at the house idea is viable for me also, since i use to refill the propane forklifts in a past job, we have a couple companies that if you pay for the propane, they will provide the tank for storage.... its just an issue of the filling equipment, and paying for that first full bulk tank

oohh Lorna...... thats for a swap/purchase
you swap for 24 bucks, or buy for 50 bucks

When we were living in Cordele GA, we could either refill our tank for $25 or swap for $16 at the Amerigas tank swap at Home Depot (back then - 2005 thru 2007- the tanks were the right weight... we checked). Only place that we have ever run into that. But since then, I always know what it costs to swap a tank BEFORE I refill. Wal-Mart has consistently been the cheapest tank swap price (not refill). Or rather... all the Wal-Marts that I have priced have been cheaper. That's been... Perry, Clayton (GA), Franklin (NC), Elizabethton, Tiftonia (TN), Socorro, Los Lunas, Roswell (NM), Corpus Christi, Rockport-Fulton, Portland (TX)
 
BTW, I haven't bought a new tank outright since 1986.
 
 

... although i have pondered having a way to tie in a 20lb tank for extended stays or emergencies...

Piece of cake....



The top pic is the last "change" since we had to change out the grill hose (leak)
2nd pic is a shot of the permanent mount LP tank & quick connect on the Class C
3rd pic is the ""extend-a-stay" how it was in TX. And I do like shut off valves.
 
We have one side going to the RV (in these pics it was the Class C) and the other side going to the gas tabletop grill. But you could hook up another 20# tank. These are easy to put together. The one pictured was left on the Class C that my daughter is still living in (it's her's now). We built another setup for the bus. The bus one will eventually get a 2nd 20# tank and auto changeover added to the mix. The grill will get piped to the other side of the bus (near the entry door). We use LP quick connects on our setups. We have also used the setup on the Class C to run a 100# tank when we wintered over in NC. We left our 100# tank in NC since we didn't want to transport it and my Moms 100# LP tank was so far out of date and in poor condition that we were told not to bring it back for refill.

lornaschinske

KurtSara

I will never swap mine until the tanks need testing, we always fill to start the smoker with a full tank.

You must be lucky enough to have fill stations that are open on the weekends and staffed by people who know how to fill a tank. Our last tank that we had filled  was completely empty. Moron put 3 gallons in it and said it was full. In Socorro, all the fill station (all two of them) closed down on Friday between Noon and 3PM. If it was a holiday weekend, they may or may not open back up on Monday morning. I used to be one of those folks who NEVER swapped a tank. I had the luxury of sitting in my yard and cleaning up a tank then repainting it. When you live in campgrounds, there are many things you no longer do. Upside is I no longer have to mow the grass. Thank God I'm "houseless"!!!!

I live in a small town, population 5000, I can get propane filled at 4 places or exchanged at 2 places, out of the 4 that fill, only one place weighs the tank and you pay for what you buy, that is where I get mine refilled, and they are open 7 days a week.