Compressed fluid spraying pistol

A spraying pistol especially for applying hardening fluids onto surfaces and operated by a pressure medium including a tank for the spraying medium, a spraying head with a distributing chamber surrounding essentially concentrically a nozzle, a jet needle having a piston means, said jet needle contacted by a pull-off for opening the nozzle against the pressure of a closing spring which is supported in a locking cap at the body of the pistol, characterized by that said nozzle with its jet needle and tank together with a connecting channel form an exchangeable medium inset insertable into a seat of the pistol body and is locked by said locking cap with said piston means holding closed said connecting channel in a rest position and opening said connecting channel when said jet needle and said piston means move together to an operating position with said nozzle open allowing said pressure medium to cause hardening fluid to flow from said tank through said connecting channel out the open nozzle.