HOSE AS 2455381 - Caterpillar

The air dryer is located under the cab and in front of the left front wheel. Air flows from the air compressor to the air dryer. The air dryer will remove the contaminants and moisture from the air system. When the air compressor governor reaches the cutout pressure. The air compressor governor sends an air pressure signal to the purge valve in the bottom of the air dryer. The purge valve opens. Air pressure that is trapped in the air dryer is exhausted through the desiccant, an oil filter, and the purge valve.A relief valve is located on the air dryer in order to protect the air system if the air compressor governor malfunctions. A heating element in the bottom of the air dryer prevents moisture in the dryer from freezing in cold weather.The Charge Cycle of an Air Dryer
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(1) Air dryer (2) Check valve (3) Orifice (4) Desiccant cartridge (5) Purge volume (6) Purge orifice (7) Oil separator filter (8) Control port (9) Air supply port (10) Check valve (11) Purge valve (12) Exhaust (13) Heater (14) Sump (15) Delivery portWhen the air compressor is loaded, air that is under pressure is sent from the air compressor through air supply port (9) into air dryer (1). When the air enters air dryer (1), the velocity (speed) of the air decreases and the air is cooled. Much of the oil and water in the air is condensed. The oil and water will then drop into sump (14). The air flows to the bottom of air dryer (1). Then the direction of the air is reversed allowing more oil and water to drop into sump (14) .The air flows through oil separator filter (7) that is between the outer shell and the inner shell of the cartridge. Oil separator filter (7) removes water in the liquid form as well as more oil and foreign materials. The air is still saturated with water.The air that still has water vapor is cooled as the air exits oil separator filter (7). The air continues upward out of oil separator filter (7) .When the air reaches the top of the cartridge, the air reverses the direction of flow. The air enters the desiccant drying bed (6). The air flows through desiccant cartridge (4) and the air becomes progressively dryer as the water vapor adheres to the desiccant material. This process is called adsorption. Desiccant cartridge (4) uses the process of adsorption typically in order to remove most of the water vapor from pressurized air.Most of the dry air exits the top of desiccant cartridge (4) through check valve (2) in order to fill purge volume (5). Some air will also exit through orifice (3) next to check valve (2) .Dry air flows out of purge volume (5) through check valve (10) and out delivery port (15) to the first reservoir of the air system.The air dryer will remain in the charge cycle until the pressure for the air system builds up to