US Patent 8146193 Launcher for tube cleaning projectiles

A launcher for heat exchanger tube cleaning projectiles using operator selected compressed air application for manipulating launcher operating components including hydraulic bolt, projectile plunger, and water valve to fire projectile with pressurized water, and to reset operating components for subsequent projectile firings. Launcher has means for venting heat exchanger tube over- or under-pressure occurring in practice, and further has visual indicator of force applied in firing projectiles, and of tube being clear after exiting of projectile from the tube.