The United States is one of the world’s largest users of propane gas, according to need.org. Nearly six million American homes, mostly in rural areas without natural gas, use propane as their major energy source for heating. It’s also a vital energy source for businesses in the manufacturing and agricultural sectors. But how much do you really know about propane? These three facts will help you understand more about this valuable gas and responsible usage. You Can Get Propane Delivered Image via Flickr by jasonwoodhead23 American propane users often bring their empty propane cylinders or tanks to local propane dealers.…