Pneumatic tools work by air pressure. This force is what causes the system to work; in other words, it is the power that drives the machine. Air pressure is provided by an air compressor. This machine has a gas-powered pump mechanism that continually forces air into a steel container tank until the air becomes pressurized. The pneumatic tool is hooked up to a hose that is attached to the tank via an air valve.
The Pneumatic Air Hose
The air from the air compressor is under constant pressure. But it has a release valve that is only activated or opened when the pneumatic tool's air hose is connected. Once connected it opens the valve and pressurized air escapes under great force into the hose. The hose has another air release valve on the end which remains closed until it is attached to the air gun. Once attached, the airway is completely open and pressurized air is being fed directly into the gun.
Each pneumatic tool, whether it is a hammer, ratchet, sand blaster or other air-powered tool, has its own release valve or firing pin. A pneumatic air gun also has a safety mechanism on the tip. Only when the tip is pressed against something is the firing mechanism engaged. When the trigger is pulled on the pneumatic tool, this firing "pin" opens a valve inside the gun and pressurized air flows through the tool. This air will either turn a crank or engine that operates gears (as in a ratchet tool) or course through the barrel and shoot a nail at high velocity.