Propane is a liquid and is sold by liquid measure (gallon) or by weight (pound). When buying by the gallon:

• Look to see that meter starts on zero.

When buying by the pound:

• Look to see that the cylinder is on the scale.
• Look to see that the scale arm is balanced before the tank is filled. This is your empty weight.
• Read the total weight when the container is filled.
• Subtract the empty weight from the total weight. This is your net weight of propane purchased.

For all types of sales:

• When the meter stops, the numbers should stop.
• Ask for the price per gallon or per pound before filling/re-filling a tank.
• Get a receipt.
• Check that the receipt has the correct quantity, unit price and total price.

Note:

It is not legal in Maryland to charge a customer a flat rate set dollar amount to re-fill a propane tank. And, it is not legal to add a charge for the labor of filling the tank (except the first time a tank has ever been filled a “purge” fee may be charged).

For example:

“$16.99 for a 20 lb tank re-fill” is not a legal method of sale
“$4.00 per gallon for propane” is a legal method of sale as is “Propane, $5.00 per pound” ​​​