High flow valve to provide optimum performance. Controls excess air flow (SCFM) in only one direction. Automatically senses change in air flow and shuts off the flow in the event of a surge in excess of valve flow rating thus preventing hose whip. Solid brass body and valve. Stainless steel spring and roll pin. Used in temporary plant/factory air lines, construction sites, shipyards or utilities. Not for use in applications where 100% of the available air is required like sand blast, pile driving rigs, expansion joint blow down pipes, etc.