Pneumatic press double valves, also referred to as dual air valves or press safety valves, are used to control the air actuated systmes which must always exhaust to a safe position. when used on spring loaded ctuches and brakes for mechanical power presses, they function as 3/2 air valves, normally closed position. İn other words, with the solenoids deenergized, this valve exhausts air from clutch brake unit (port 2 to 3 )  while preventing the inlet pressure from reaching the working port. When the solenoids are energized , air pressure is supplied to the clutch/brake unit , allowing the clutch to engage.

Herion's XSz double valve is designed for self-checking in accordance with OSHA and ANSI. This design with it's unique cross flow pattern and air logic monitor is a revolutionary technological advancement to double valve design.This design was patented by herion