Atlas Copco Inlet Valve Kit Replacement – 2906017500

The Atlas Copco 2906017500 is an Inlet Valve Kit used to service the air-intake valve of applicable ZR/ZT 75–90 oil-free compressors. The inlet valve controls the amount of atmospheric air entering the compressor according to the compressor’s loading requirements.

During loaded operation, the valve opens to allow the required quantity of air into the compressor. During unloading, the valve closes or restricts the intake, reducing the amount of air being compressed and helping the compressor operate efficiently.

Working Process

1. Air Intake – Atmospheric air approaches the compressor inlet.
2. Loading Command – When compressed air is required, the control system commands the inlet valve to open.
3. Valve Opening – The inlet valve permits air to enter the compressor element.
4. Compression – The incoming air is compressed by the compressor element.
5. Pressure Regulation – The valve position is controlled according to compressor demand.
6. Unloading – When system demand decreases, the inlet valve closes/restricts the air intake.
7. Reduced Compression – Less air enters the compressor, reducing unnecessary compression work.
8. Reloading – When pressure falls below the required level, the valve opens again.
9. Continuous Control – This loading/unloading cycle is repeated automatically during operation.

Main Functions

• Controls compressor air intake.
• Regulates compressor loading and unloading.
• Helps maintain required system pressure.
• Reduces unnecessary energy consumption during unloading.
• Supports stable compressor operation.
• Helps prevent unwanted air leakage.
• Restores inlet-valve performance during maintenance.

Official Kit Components

Atlas Copco lists these components for 2906017500:

Role of the Diaphragm & Membrane

The diaphragm and membrane are important control components within the inlet-valve assembly. They respond to control pressure and help move the valve mechanism between loading and unloading positions.

The O-rings and gaskets provide sealing between mating components and prevent unwanted air leakage.

Possible Failure Symptoms

A worn or damaged inlet valve can cause:

• Compressor unable to load correctly.
• Compressor unable to unload correctly.
• Continuous loading.
• Excessive energy consumption.
• Unstable pressure.
• Air leakage.
• Slow pressure build-up.
• Abnormal valve operation.
• Compressor alarms or shutdown.

Maintenance Procedure

1. Shut down the compressor according to the applicable Atlas Copco service procedure.
2. Isolate the electrical supply.
3. Fully depressurize the compressor.
4. Allow the equipment to cool.
5. Isolate the control-air supply where applicable.
6. Remove the inlet-valve assembly.
7. Inspect the valve, diaphragm, membrane and sealing surfaces.
8. Remove worn components.
9. Clean the mating surfaces.
10. Install the replacement components supplied with 2906017500.
11. Install the O-rings without twisting or damaging them.
12. Correctly position the diaphragm and membrane.
13. Reassemble the inlet valve.
14. Restart the compressor.
15. Check loading and unloading operation.
16. Verify pressure control and inspect for leakage.

Service Benefits

Using the 2906017500 Inlet Valve Kit helps:

• Restore proper compressor air intake.
• Improve loading/unloading control.
• Reduce compressed-air losses.
• Support stable operating pressure.
• Reduce unnecessary energy consumption.
• Improve compressor reliability.
• Reduce maintenance-related downtime.

Technical Summary

Recommended catalog title: Atlas Copco 2906017500 – ZR/ZT 75–90 Inlet Valve Kit for Oil-Free Compressors, 2906-0175-00.

Compatibility note: Verify the compressor model and serial number before ordering. Atlas Copco recommends using the machine serial number/Parts Book to confirm the correct spare part for the specific machine.