Wheel end valve for central tire inflation system

A modular wheel end valve assembly for a central tire inflation system comprising a valve body having only a first and a second fluid connection from the exterior to the interior thereof, said first fluid connection defined by a first port for connection to a selectively pressurized and exhausted conduit, said second fluid connection defined by a second port for connection to the interior pressurized chamber of an inflatable tire, said valve assembly comprising first valve means responsive to pressurization of said selectively pressurized and exhausted conduit to assume a first position for establishing fluid communication between said first and second ports and responsive to exhausting to atmosphere of said selectively pressurized and exhausted conduit to assume a second position for blocking fluid communication between said first and second ports thereof, said first valve means comprising a first diaphragm having a first surface exposed to fluid pressure at said first port and an opposed second larger surface, said valve assembly comprising second valve means constantly in fluid communication with said second port and responsive to a sensed pressurization of said interior chamber of said tire being less than a predetermined minimum reference pressure to automatically maintain said first valve means in said second position thereof, said assembly characterized by:

• said second valve means comprising a second diaphragm having a third suface constantly exposed to fluid pressure at said first port and an opposed fourth surface substantially greater surface constantly exposed to fluid pressure at said second port, said second diaphragm normally biased by fluid pressure in said second port exceeding said minimum reference pressure to block fluid communication between said first port and said second surface and responsive to fluid pressure at said second port not exceeding said minimum reference value to establish fluid/communication between said first port and said second surface.