Liquefied petroleum gas, commonly known as LP gas, is a mixture of propane and butane. It is a byproduct of methane (natural gas) production and crude oil refining. It is widely used by consumers as a portable high-energy gaseous fuel for applications such as cooking, heating or weed burning and as a motor fuel in confined areas.

Sold in Cylinders

LP gas for consumer use is supplied in cylinders that you attach to your LP gas appliance, such as a barbecue grill or portable stove. The cylinders are also known as bottles. There are six standard types of steel cylinders. There also are four standard types of aluminum cylinders for applications where light weight is important. The LP gas industry developed a standard attachment valve used on all LP gas cylinders, making them interchangeable.

Most Common Type

The most common LP gas cylinders are meant to be used in the vertical position, according to First is the familiar 20-lb. bottle used singly in gas grills and in pairs on camping trailers or motor homes. It is 12.25 inches in diameter, stands 18 inches high and weighs 38 lbs. when full. It holds the equivalent of 4.7 gallons of fuel. This type of bottle, when made of aluminum, weighs 34 lbs. when full.

Other Types

There also is a 30 lb. cylinder in steel or aluminum. It’s 12.25 inches in diameter, stands 24-inches high, holds 7.1 gallons of fuel and weighs 54 lbs. (steel) or 48 lbs. (aluminum) when full. The 40 lb. cylinder in steel or aluminum is 12.25 inches in diameter, stands 29 inches high, holds 9.4 gallons of fuel and weighs 70 lbs. (steel) or 60 lbs. (aluminum) when full.

Biggest Cylinders

The 50 lb. and 100 lb. vertical cylinders are the big boys of the consumer cylinder lineup, and come only in steel, according to The 50 lb. cylinder is 15 inches in diameter, stands 40 inches high, holds 11.4 gallons of fuel and weighs 92 lbs when full. The 100 lb. cylinder is 14.5 inches in diameter, stands 48 inches high, holds about 24 gallons of fuel and weighs 170 lbs. when full.

Forklift Cylinders

The LP gas industry also offers 33 lb. horizontal cylinders in steel or aluminum for LP gas as a motor fuel in forklifts, high-powered lawnmowers for large campuses, and floor buffers for large indoor areas, according to These cylinders are 12.5 inches in diameter, 28 inches long, hold 7.9 gallons of fuel and weigh 69 lbs. (steel) or 56 lbs. (aluminum) when full.