The function of the integrated solution air dryer (AD-IS) is to provide vehicles with integrated vehicle air dryer, purge reservoir, governor and a number of charging valve components in a module. These have been designed as an integrated air supply system.

The AD-IS collects and removes air system contaminants in solid, liquid and vapor form before they enter the brake system. It provides clean, dry air to the components of the brake system which increase the life of the system and reduce maintenance costs. Daily manual draining of the reservoirs is eliminated.

The function of the pressure protection valves is to protect each reservoir from a pressure loss. Each of the pressure protection valves in the AD-IS may have different pressure settings. These are factory set and CAN NOT be changed or adjusted.

The air dryer consists of a "spin-on" desiccant cartridge secured to a base assembly. The base assembly contains a check valve assembly, safety valve, heater and thermostat assembly, pressure protection valves, threaded air connections and the purge valve assembly.

The removable purge valve assembly incorporates the purge valve mechanism and a turbocharger cut-off feature that is designed to prevent loss of engine "turbo" boost pressure during the purge cycle of the AD-IS .

The integrated solution air dryer (AD-IS) is designed to receive compressed air from the vehicle air compressor, clean and dry the air, deliver the air to the vehicles primary and secondary reservoirs and accessories, and control the compressor/dryer charge cycle.

The integrated solution air dryer (AD-IS) alternates between 2 operational modes or "cycles" during operation: the charge cycle and the purge cycle.

When the compressor is loaded (compressing air) compressed air flows through the compressor discharge line to the inlet (1 inch) port of the air dryer body. The compressed air includes contaminants such as oil, oil vapor, water and water vapor.

Traveling through the discharge line and into the air dryer, the temperature of the compressed air falls, causing some of the contaminants to condense and drop to the bottom of the air dryer purge valve assembly, ready to be expelled at the next purge cycle. The air then flows into the desiccant cartridge, where it flows through an oil separator which removes oil and solid contaminants.

Dry air exits the desiccant cartridge through the center of the base assembly. The air then flows to the delivery check valve and also through an orifice into the purge reservoir. The delivery check valve opens, supplying air to the pressure protection valves simultaneously, the safety valves and also the governor. The purge reservoir fills, storing air that will be used to reactivate the desiccant during the purge cycle.

When the air pressure reaches approximately 106 psi, the pressure protection valves will open and air will be supplied to the primary reservoir, secondary reservoir and accessories. The air dryer will remain in the charge cycle until the air brake system pressure builds to the governor cut-out setting of approximately 130 psi.

When the air brake system pressure reaches the cut-out setting of the governor, the governor unloads the compressor and the purge cycle of the air dryer begins.

The governor unloads the compressor by allowing air pressure to fill the line leading to the compressor unloader mechanism, causing the delivery of compressed air to the integrated solution air dryer (AD-IS) to be suspended.

Similarly, the governor also supplies air pressure to the AD-IS purge control channel. The AD-IS purge valve piston moves down in response to the air pressure, causing the purge valve to open to the atmosphere, and the turbo cut-off valve to close off supply of air from the compressor. Water and contaminant which have collected in the purge valve are expelled immediately when the purge valve opens. Air which was flowing through the desiccant cartridge changes direction and begins to flow forward toward the open purge valve. Oil and solid contaminants collected by the oil separator are removed by air flowing from the purge reservoir through the desiccant drying bed to the open purge valve. The initial purge and desiccant decompression lasts only a few seconds and is evidenced by an audible burst of air at the AD-IS exhaust.

The actual reactivation of the desiccant drying bed begins as dry air from the purge reservoir flows through the purge orifice into the desiccant bed. Pressurized air from the purge reservoir expands after passing through the purge orifice, pressure is lowered and volume increased. The flow of dry air through the drying bed reactivates the desiccant material by removing the water vapor adhering to it. Approximately 30 seconds are required for the entire contents of the purge reservoir of a standard AD-IS to flow through the desiccant drying bed.

The delivery check valve assembly prevents air pressure in the brake system from returning to the air dryer during the purge cycle. After the purge cycle is complete, the air dryer is ready for the next charge cycle to begin.