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/.
Rated 1 out of 5 by Cmac from Be aware that the 20 lb propane exchange tanks are only 3/4 full. They don't show it on the webs... Be aware that the 20 lb propane exchange tanks are only 3/4 full. They don't show it on the website but their 20 lb tanks only have 15 lbs of propane in them and they cost more than a full refill elsewhere. Most people would not notice this, just another reason to shop at a smaller local business.