Problem filling 5 gal LP tank - help please

The last 5 Gallon LP tank I bought a couple of years ago was already purged at the factory. Had a sticker on it stating that it did not need to be purged.

Francesca Knowles wrote:
A five pound tank holds about a gallon, is much smaller- and, weirdly, is much more expensive to buy than a twenty pounder!

Economy of scale. How many 20 pound tanks do they sell for every 5 pound tank? Think about it.

If it costs $10,000 to set up the equipment, that has to be amortized over the entire run. If they make 1,000 tanks, they have to increase the cost by $10 just to cover equipment setup.

Now, if they produce 1,000,000 tanks, they only have to add 1 cent to the price of each tank to cover the equipment setup.

Fixed costs divided by number of pieces sold. VERY few 1 gallon tanks are sold, but 5 gallon tanks are sold by the truck load.

jaycocamprs wrote:

And some places (Costco) want to charge as much to fill it as they do the twenty pounder. So they don’t get to fill either my five-pound or my thirty-pound cylinders.

At costco I only pay for what they put in. I love being able to top off a tank for $3.

Francesca Knowles wrote:

A five pound tank holds about a gallon, is much smaller- and, weirdly, is much more expensive to buy than a twenty pounder!

And some places (Costco) want to charge as much to fill it as they do the twenty pounder. So they don’t get to fill either my five-pound or my thirty-pound cylinders.

Chances are It was improperly filed the first time, if it wasn’t filled by weight… The correct fill is 80% but correctly filled is 80% @ 60* or to be sure it is 4.24 pounds per gallon of propane at any temperature…

So if the tank was filled the first time early in the morning after a cold night of say 48* to 80% in volume the tank is 2% overfilled… if it wasn’t sitting on a true level spot it could be more or less…
Now on the second fill it was 72* ambient temp and a sunny day… the gas in the tank would be 2% more by volume and 4 % more than the first fill… this can be a dangerous situation while transporting the tank, as it was overfilled enough that it could have discharged propane vapor or even liquid through the relief valve into its storage compartment, or worse yet would be to get liquid propane to the appliance designed to work on vapor only… it also explains why it is still too full even after using its propane…

This is the reason you want properly trained people dispensing the product…

49 CFR 170-179) for filling cylinders, storage tanks, tank trucks, and tank cars allow adequate vapor space for liquid expansion as the result of a change in atmospheric temperature.

klm wrote:
OP back, with an embarrassing update :( I took the tank to the local lp dealer. He explained all about purging the tank, but said that since the tank works fine supplying lp to the grill - not an issue with nitrogen (? I think that's it). He also said that moisture in these smaller tanks is rare. So, now for the embarrassing part - he weighed the tank - it is too full to accept any fuel. Boy, am I a dummy. We used the tank all spring and summer - short grill times - wow, not sure how it can still be near full - but it is. We are used to using those throwaway green bottles, guess we have a learning curve with this 5 lb lp tank. In the meantime, thanks all - I did learn a lot from you -

I bought a 1 gallon (5 pound) LP tank when we bought the RV. I had it filled 6 years ago, and it is still going strong. And we grill a lot when camping. They hold a LOT of propane.

I am a certified Propane filler. The probable problem is that the float on the OPD valve is stuck. This can occur if the tank has no liquid in it and that the operator opened the valve too rapidly at the beginning of the filling process...this many times happens on the first fill whether the tank has been purged or not. Since propane boils to a gas at -60 degrees F, as soon as the liquid hits the bottom of the tank there is a huge force of gas upward. The float can be violently thrown up, get stuck and can even be damaged. It has been suggested that you drop the tank. This is good advise but turn it upside down and drop it on the top. The second solution if there is a gas lock is to have the filler connect the tank to their purging device and release pressure on the OPD valve. If neither of these work the tank's OPD valve has probably been damaged.

:B

Thanks for the "is my face red" update, O.P.!

FYI:
Weight is the most accurate measure of how much propane is in the bottle- I use a bathroom scale to check mine.

Per tank size:
If you're using a garden-variety bulk tank about the size of the ones at cylinder exchanges, you were right the first time. That would be a "five gallon", more commonly referred to as a twenty pounder.

A five pound tank holds about a gallon, is much smaller- and, weirdly, is much more expensive to buy than a twenty pounder!

OP back, with an embarrassing update :( I took the tank to the local lp dealer. He explained all about purging the tank, but said that since the tank works fine supplying lp to the grill - not an issue with nitrogen (? I think that's it). He also said that moisture in these smaller tanks is rare. So, now for the embarrassing part - he weighed the tank - it is too full to accept any fuel. Boy, am I a dummy. We used the tank all spring and summer - short grill times - wow, not sure how it can still be near full - but it is. We are used to using those throwaway green bottles, guess we have a learning curve with this 5 lb lp tank. In the meantime, thanks all - I did learn a lot from you -

Fill adapters & the fitting on the RV are 2 different animals.