Propane tank

h45wt wrote:

Old-Biscuit wrote:

A FULL (80%) 20lb propane cylinder IS 4.7 gallons (20 divided by 4.2 equals 4.76)

20lb is where bleeder will spew 'liquid'...which is also where OPD shuts off filling

30lb...7.2 gal (80%)

I don't think you are correct about the 30lb tank. They are about 7 gal capacity so 80% would be 5.6 gals which is where my tanks shut off when filling.

One gallon of liquefied propane weighs 4.24 pounds.

Every DOT certified LPG tank (20 & 30 pounders, there are others, but for this thread we will discuss these) has a water capacity (WC) stamped on the collar of the tank. These tanks are certified to hold 80% of the stamped WC in liquefied propane.

Every manufacture of DOT LPG tanks has a WC number that their type of tank is certified to hold. These numbers may be different for different tank manufactures.

If a particular manufacture's tank has a WC of 25#s than at 80% full of propane, that would be 20#s of LPG. 25#s of water x 80% equals 20#s of LPG.

If a particular manufacture's tank has a WC of 38#s than at 80% full of propane, that would be 30.4#s LPG. 38#s of water x 80% equals 30.4#s of LPG.

Not many LPG dealers fill DOT 20# and 30# tanks by weight any longer. Most just fill until OPD valve shuts off the flow of LPG.

OPD valves are installed in tanks to deliver LPG to the 80% level of volume of WC stamped on the tank.

Sounds confusing, but is not. The amount of LPG put into different tanks can vary according to the certified WC stamped on the coller.

Lakeside

fishing2 wrote:
If the station fills on a scale the weight of the hose needs to be added to the tare weight.

I think all is connected and the scale is zeroed out. Then the propane flows.

Kayteg1 wrote:

SidecarFlip wrote:
Propane sells on weight not volume ,,,.

Can you post a picture of such scale?
I've been filling up propane several times a year and all stations I have been to -have flow meter scaled in gallons.

Not sure I can do that in as much as it's not my business and I hunt with the owner (who is fishing right now) but I'll ask him. If I can I can post it. if not, you'll have to take my word for it.

Lakeside will be by in September and I can drive him there and he can see as well (for a collaborating witness) if I cannot.

If the station fills on a scale the weight of the hose needs to be added to the tare weight.

My 30 pounders shut off right at 7.0 - 7.2 gallons either by OPD or the bleeder.

SidecarFlip wrote:
Propane sells on weight not volume ,,,.

Kayteg1 wrote:
Can you post a picture of such scale?

its going to have to be a pretty old picture - maybe even a black and white ;)

Old-Biscuit wrote:

A FULL (80%) 20lb propane cylinder IS 4.7 gallons (20 divided by 4.2 equals 4.76)

20lb is where bleeder will spew 'liquid'...which is also where OPD shuts off filling

30lb...7.2 gal (80%)

I don't think you are correct about the 30lb tank. They are about 7 gal capacity so 80% would be 5.6 gals which is where my tanks shut off when filling.

SidecarFlip wrote:
Propane sells on weight not volume ,,,.

Can you post a picture of such scale?
I've been filling up propane several times a year and all stations I have been to -have flow meter scaled in gallons.

SidecarFlip wrote:
they are bottles not tanks

bottles are made of glass, its a propane cylinder

but who really cares?

How old is the regulator? Have you performed any leak check?

Maybe he under filled. I would try to assume he put in 4 gallons and you paid for 4 gallons. Go to a real propane dealer and explain your concerns in advance.