Installation guide · Air-Pak dryers

Regeneration Flow Cut-Off Kit

Stop purge flow while your compressor is idle. This kit ties the dryer’s regeneration cycle to the compressor’s pressure switch, so the dryer only purges while the compressor is pumping.

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Kit includes

What’s in the box

1 Aluminum adapter plate
1 Four-way valve with three (3) 90° fittings
1 Solenoid with 6″ wire lead
1 ¼” nylon tubing
3 8-32 round head machine screws
4 10-32 Phillips machine screws
3 O-rings (small)
2 O-rings (large)

Before you begin

Relieve all air pressure from the air dryer assembly before performing this procedure.

The procedure

Four steps to install.

Have a center punch and a drill with a 3/16″ bit on hand. Torque values are listed in each step.

STEP 01

Prepare the manifold

Remove the manifold, mark and drill the pilot hole, and set the four-way valve aside.

STEP 02

Install low flow components

Fit the new valve, O-rings, and adapter plate, then reinstall the manifold.

STEP 03

Prepare the original valve

Plug the “2” port, mount the original valve on the plate, and connect the air lines.

STEP 04

Electrical

Reconnect the MLT, install the solenoid, and wire it to the compressor’s pressure control.

Step 1 of 4

Preparing the manifold

  1. Disconnect the air line from the dryer’s outlet port.
  2. Disconnect the two (2) ¼” air lines from the back of the air control valve.
  3. Remove the four (4) bolts fastening the manifold on the right side.
  4. Place the aluminum plate as illustrated and position it over the four holes in the manifold.

Important: The pilot hole (yellow) must be at the bottom, as shown.

  1. Temporarily secure the plate to the manifold with four (4) Phillips screws.
  2. Place a center punch through the pilot hole and mark the manifold casting.
  3. Remove the four (4) bolts fastening the manifold on the left side. Then remove the four (4) Phillips screws, the aluminum plate, and the manifold assembly from the dryer.
  4. Discard the two (2) large O-rings and place the manifold assembly on a clean work area.

Note: Clean and inspect the regeneration valves, then place them back into the valve cavities.

  1. Remove the thumb screw and MLT from the air control valve.
  2. Remove the three (3) screws holding the four-way valve. Set the screws and valve aside for later installation.
  3. Drill a 3/16″ hole through the center-punch mark in the manifold.
  4. Clean all drilling debris from the manifold.
Preparing-Manifold

Step 2 of 4

Installing low flow components

  1. Lubricate one (1) small O-ring and insert it into the new groove in the manifold.
  2. Position the new four-way valve on the bottom of the manifold and secure it with three (3) 10-32 round head machine screws. Tighten to 15–20 in-lb.
  3. Install a new small O-ring into the groove on the back side of the aluminum plate (the side where the 4 holes are not countersunk).
  4. Lubricate and install two (2) new large O-rings onto the shoulders of the manifold.
  5. Reinstall the manifold into the dryer adapter castings.
  6. Install the four (4) left-side bolts and hand-tighten.
  7. Place the aluminum plate on the right side of the manifold with the pilot hole over the drilled hole, and secure it with four (4) Phillips screws.
  8. Tighten all four bolts and machine screws to 45–65 in-lb.
  9. Reinstall the air line to the dryer’s outlet port.
Installing-Low-Flow-Components
Installing-Low-Flow-Components-2

Step 3 of 4

Preparing the original four-way valve

  1. Remove one (1) 90° brass fitting from the “2” position and insert a ⅛” pipe plug.
  2. Install the original four-way valve on the aluminum plate using the three (3) screws removed earlier. Tighten to 15–20 in-lb.
  3. Connect the supplied ¼” air line (cut to fit) from the original valve to the new four-way valve.
  4. Reconnect the two (2) ¼” air lines you disconnected earlier to the back side of the new air control valve (not illustrated).
PREPARING-ORIGINAL-FOUR-WAY-VALVE

Step 4 of 4

Electrical

  1. Reconnect the original MLT onto the new valve, secure it with the thumb screw, and connect it to a 110–120 V AC surge-protected outlet.
  2. Install the new solenoid with 6″ lead onto the original four-way valve and secure it with the thumb screw.
  3. Connect the three (3) power leads to the power source that controls the compressor motor’s low-pressure “On” and high-pressure “Off” cycles.
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Electrical

Troubleshooting

How the Regeneration Cutoff Solenoid works.

The RCS switches the dryer’s purge on and off in step with the compressor’s pressure control switch.

COMPRESSOR ON

Dryer cycles normally

While the compressor motor runs, the RCS lets pilot air reach the air control valve under the manifold. The dryer cycles pneumatically every two minutes with the Micro Logic Timer (MLT).

COMPRESSOR OFF

Purge flow stops

At cut-off pressure, power to the RCS shuts off and the air control valve switches, blocking the pilot signal. The MLT keeps cycling electrically, but the dryer no longer cycles pneumatically, so there is no purge flow while the compressor is idle.

WHAT’S NORMAL

A short burst of air

Each time an AIR-PAK dryer cycles, one exhaust port (muffler) releases a momentary burst of air. Four-cartridge MLT systems regenerate two cartridges at once, one per dryer unit: for example, cartridges 1 and 3 charge while 2 and 4 regenerate.

RCS (Regeneration Cutoff Solenoid)

Need help?

Questions about your installation?

Tell us which dryer you’re working on, and our engineers will help you get the cut-off kit installed and running.