Spraying apparatus for applying friction modifying material to railroad rail

A spraying apparatus for applying a friction modifying fluid to a railroad rail, comprising: a nozzle body disposed in a housing; a fluid inlet conduit in fluid communication with an opening in the housing; a fluid inlet disposed in the housing in fluid communication with a first fluid conduit defined by or disposed in the nozzle body; wherein the first fluid conduit runs from fluid inlet to a hollow nozzle tip body disposed on and protruding through a bottom of housing; a control fluid supply line and an atomizing fluid supply line each partially disposed in the housing; wherein the control fluid supply line injects a pressurized control fluid against a piston assembly disposed in a piston cavity; wherein the piston assembly carries stopper needle which is biased towards hollow nozzle tip body by a spring so that the needle closes a nozzle tip opening of hollow nozzle tip body.