Bendix Commercial Vehicle Systems AD-IS EVERFLOW ASSEMBLY User Manual

Bendix® AD-IS® EverFlow™ Assembly

SD-08-2417

EVERFLOW™ MODULE

GOVERNOR

SEC

DELIVERY TO

SECONDARY

RESERVOIR

PRESSURE

PURGE RESERVOIR

RES

GOVERNOR

RESERVOIR (2)

PURGE VALVE

EVERFLOW ELECTRONIC

MODULE

™

AD-IS® EVERFLOW™ ASSEMBLY

PRI

DELIVERY TO

PRIMARY

RESERVOIR

SAFETY VALVE

DESICCANT CARTRIDGE

AD-IS® AIR DRYER

MOUNTING

HOLES - 4

PURGE

RESERVOIR

UNL

GOVERNOR

UNLOADER (2)

GOVERNOR

EXH

GOVERNOR

EXHAUST

AD-IS® AIR DRYER

PART NUMBER

STAMPED HERE

SUPPLY FROM COMPRESSOR

MOUNTING

BOLTS (3)

HEATER /

THERMOSTAT

PRESSURE PROTECTION

VALVES

AUXILIARY

DELIVERY PORTS

FIGURE 1 - AD-IS® EVERFLOW™ ASSEMBL Y, AD-IS® AIR DRYER, AND EVERFLOW™ ELECTRONIC MODULE

AUX2

AUXILIARY

DELIVERY PORT

AUX1

DESCRIPTION

The function of the AD-IS® EverFlow™ assembly is to provide heavy vehicles that use large amounts of air with a dryer system that facilitates continuous ﬂ ow drying. This assembly provides, in a single package, all the components necessary to operate two dryers. The assembly determines if high air demand is needed and continuously switches between dryers every 30 seconds until the high air demand ceases. When high air demand is not needed, the assembly uses the dryers as if in a normal braking system. Each dryer cycles as the air brake system requires. This feature prevents wasted air and unnecessary cycles. The assembly uses an electronic module that determines air demand and sequences the dryers for maximum efﬁ ciency.

The AD-IS 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 increases the life of the system and reduces maintenance costs. Daily manual draining of the reservoirs is eliminated, but still may be mandated by law.

The function of the pressure protection valves is to protect each reservoir from a pressure loss in the other reservoir or a pressure loss in an air accessory . Each of the pressure protection valves in the AD-IS® air dryer may have different pressure settings, but these are factory set and must 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 delivery 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® air dryer. For ease of maintenance, all replaceable assemblies can be serviced without removal of the air dryer from its mounting on the vehicle. Refer to Preventive Maintenance section.

These units will not operate properly with a Holset type compressor. For discharge line unloaded compressors a three way valve must be installed upstream of the air dryer. Contact Bendix Commercial Vehicle Systems for additional information.

AD-IS® EVERFLOW™ ASSEMBLY OPERATION

GENERAL (Refer to Figure 2)

The AD-IS® EverFlow™ assembly is designed to receive compressed air from the vehicle air compressor. It then cleans and dries the air before delivering it to the vehicle’s primary reservoir, secondary reservoir and accessories.

air dryer collects and removes air system

Additionally , the AD-IS® EverFlow™ assembly controls the compressor/dryer charge cycle.

AD-IS® EVERFLOW™ AIR DRYER OPERATION:

GENERAL

The AD-IS

EverFlow™ assembly alternates between the dryers each time the brake system charges. During high air demand, the dryers alternate every 30 seconds to allow drying of the added volume of air. A pressure protection valve is needed after the dryers to maintain at least 70 PSIG at the dryers during high air demand. An electronic module monitors the air brake system and determines the amount of demand. The AD-IS® EverFlow™ assembly requires a signal from the delivery port of the governor into the GOV port of the EverFlow™ electronic module. The AD-IS® EverFlow™ Assembly also needs a supply air line from the secondary tank to the electronic module RES port.

This line must be 3/8 inch tubing or larger. The AD-IS® EverFlow™ assembly is primarily designed

to dry air on systems used for bulk unload and central tire inﬂ ation. The system operates best when a pressure protection valve is installed between the AD-IS® EverFlow™ assembly and the source of the high volume air. Refer to the system schematics, Figure 2. This pressure protection valve should have a minimum pressure of 70 PSIG.

Delivery pressure in excess of 175 PSIG can cause the purge valve to cycle rapidly between load and purge mode.

NORMAL BRAKE CYCLE (Refer to Figure 2)

When the compressor is charging (compressing air) air ﬂ ows through the compressor discharge line to the inlet (1 IN) port of one of the air dryers. The compressed air includes contaminates such as oil, oil vapor, water and water vapor. The air then ﬂ ows into the desiccant cartridge, where it ﬂ ows through a liquid separator which collects liquids and other contaminants.

Air Connection Function/Connection QTY

Port ID

1 Inlet Port (air in). 1

IN 21

Delivery Port out (to Primary reservoir) 1

PRI 22

SEC

Delivery Port out (to Secondary reservoir) 24

Auxiliary Delivery Port (air out). 4

AUX 1 23

Auxiliary Delivery Port (air out). 1

AUX 2 UNL Unloader Control Air (D-2A™ Governor) 2

RES Common Reservoir Pressure (D-2A™ Governor) 2

TABLE 1 - AD-IS® AIR DRYER PORT DESIGNATIONS

Schrader

Valve

From

Engine

Compressor

Governor

CON

1/4"

CON

Supply

OUT

CON

RES

CON

EverFlow

SEC

PRI

Accessories

™

GOV

CON

EFM

AD-IS

Dryer OUT

CTI System

EverFlow™ Module

RES

CON

Bulk Ofﬂ oad CTI

3/8"

1/2"

Check

Valve

Supply

Pressure

Protection Valve

(Optional)

Bulk Tanker

Primary

Reservoir

Secondary

Reservoir

Manual Valve

Compressor

OUT

Discharge Line

Unloader Valve

Note:

The AD-IS® air dryer purge piston has a purge control channel drain. This allows any condensation in this area to ﬂ ow past a diaphragm in the top of the purge piston and out through a channel in the middle of the central bolt of the purge assembly to be drained. During the purge cycle this drain is closed.

FIGURE 2 - AD-IS® AIR DRYER SYSTEM SCHEMATIC

Air then ﬂ ows into the desiccant drying bed and becomes progressively drier as water vapor adheres to the desiccant material in a process known as “ADSORPTION.” Dry air exits the desiccant cartridge through the delivery check valve and also through an oriﬁ ce into the purge reservoir. The delivery check valve opens, supplying air to pressurize the air brake system. The purge reservoir stores air that will be used to reactivate the desiccant during the purge cycle.

The air dryer will remain in the charge cycle until the air brake system pressure builds to approximately 85 p.s.i. At 85 p.s.i. the EverFlow™ electronic module is actuated and

begins 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 or other accessories. If the pressure protection valves are preset to different values the valves will open in order of lowest setting to highest setting when charging a ﬂ at system. 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 p.s.i. When air brake system pressure reaches the cut-out setting of the governor, the governor unloads the compressor and the electronic module sends a signal to one of the air dryers to purge. The governor unloads the compressor by allowing air pressure to ﬁ ll the line leading to the compressor unloader mechanism - causing the delivery of compressed air to the AD-IS® EverFlow™ assembly to be suspended. Similarly, the governor also supplies air pressure to the EverFlow™ electronic module. The electronic module uses this signal to determine the volume of air into the brake system. If the volume is normal, the electronic module sends a signal to the control port on the proper dryer. If the volume is high, the electronic module switches the dryers every 30 seconds until the air volume returns to normal. The air dryer purge piston moves down in response to a pneumatic signal from the EverFlow™ electronic module, causing the purge valve to open to the atmosphere and

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