Nearly all riveting is done with pneumatic riveters. The pneumatic riveting guns operate on compressed air supplied from a compressor or storage tank. Normally, rivet guns are equipped with an air regulator on the handle to control the amount of air entering the gun. See figure 13-10. Regulated air entering the gun passes through the handle and throttle valve, which is controlled by the trigger, and into the cylinder in which the piston moves.
Air pressure forces the piston down against the rivet set and exhausts itself through side ports.
The rivet set recoils, forcing the piston back. Then the cycle is repeated. Each time the piston strikes the rivet set, the force is transmitted to the rivet. Rivet sets come in various sizes to fit the various shaped rivet heads. Rivet set retainer springs must be used on all pneumatic rivet sets to prevent the set from being discharged from the gun when the trigger is pulled.