Numerous forklifts are made to run on propane gas. Forklifts that utilize propane are really simple to refill. The gas is stored inside a pressurized tank on the back of the truck. The propane is pushed into the engine, where it is converted into vapor and the vapor combines with air. The forklift throttle is used to control the flow of vapor. A spark plug fires up the mix of vapor and air creating pressure which makes the pistons move. The pistons turn the wheels and power the hydraulic pump.
As the kinds of forklifts that are operated by propane are clean burning and have low emissions, they are best to be used in warehouses and other buildings.
What allows a forklift to raise and transport heavy stuff from one location to another is the hydraulic system. A pump, tubes and cylinders make up the hydraulic system. The pump forces dense fluid through the tubing and into the cylinders. The build up of pressure pushes a piston, that lifts the forks. When the forks are lowered by the operator, the hydraulic fluid flows out of the cylinders and back into the pump.
Propane forklifts work well where maneuverability is required. Unlike a car, a forklift utilizes its back wheels to turn, that enables the forklift to turn quickly on a tight radius.