How much does an empty 30-pound propane tank weigh?

a typical steel "30 pound" liquid propane tank weighs about 25-28 pounds empty.

propane tank markings (on collar)

propane weighs about 4.125 pounds per gallon and a "30 pound tank" will

hold about 7.5 gallons so a full tank will weigh about 55 pounds or so.

Typical recertification stamp:

MM XXX YY E

MM -> 2 digit recertification month

XXX ->3 character Re-qualifier's registration number

YY -> 2 digit recertification year

E ->States the cylinder has been externally examined

WC -> Water capacity of the cylinder.

TW -> Tare weight of the cylinder (what the tank weighs empty)

ICC, DOT, BTE, CTC or TC -> Specification number eg. TC4BA240

10 89 -> Date of manufacture (October. 1989)