So, what you are probably re â¦ ferring to is 'energy'. The SI unit of energy is the joule (J). An alternative unit, used by electricity utility companies for the purpose of billing its consumers, is the kilowatt hour (kW.h).
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 po â¦ und tank will hold about 7.5 gallons so a full tank will weigh about 55 pounds or so. /source: wiki.answers.com/.
How Many Gallons in a 20 Pound Propane Tank? A 'full' 20 pound propane tank would contain 4.73 gallons of propane. Note that in some US tank exchange programs, the fill is something less than 20 pounds and is labelled accordingly. The image above is a typical 20 pound (9kg) propane tank.