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/.
tank on a grill. With propane weighing 4.4 pounds per gallon, the reference of the size of the cylinder determines the volume. Example of the 20 pound LPG cylinder on the grill will provide approximately 4.5 gallons of liquid propane. A 100 pound cylinder will provide approximately 20 gallons of liquid propane.