Atlas Copco Inlet Valve Overhaul Kit Replacement – 2906017600

Atlas Copco 2906017600 – Inlet Valve Overhaul Kit

The Atlas Copco 2906017600 (2906-0176-00) is an Inlet Valve Overhaul Kit designed for compatible ZR/ZT75–90 oil-free compressors.

The inlet valve controls the amount of atmospheric air entering the compressor element. Correct inlet-valve operation is essential for maintaining the required airflow, compressor capacity and stable operating conditions.

The 2906017600 kit is used during overhaul/service of the inlet valve to replace critical mechanical components that can wear during extended compressor operation.

Working Process:

During compressor operation, atmospheric air approaches the compressor through the inlet system.

The inlet valve regulates the quantity of air entering the compression element according to the compressor’s operating condition and demand.

When the compressor requires more capacity, the inlet valve opens to allow increased airflow into the compressor.

When the required capacity decreases, the inlet valve moves toward a more closed position, reducing the amount of air entering the compression element.

The valve therefore acts as an important control point between the atmosphere and the compressor element.

Inside the inlet-valve mechanism, bearings allow controlled movement of the valve components. Circlips retain the applicable components in their correct positions, while the spring provides the required mechanical restoring force.

Over time, bearings, springs and retaining components may experience wear, fatigue or deterioration.

The 2906017600 Inlet Valve Overhaul Kit provides replacement components needed to restore the mechanical condition of the inlet-valve assembly.

Official Kit Components:

Atlas Copco’s official catalog lists:

• Bearing – 1 pc
• Circlip – 1 pc
• Bearing – 1 pc
• Circlip – 1 pc
• Spring – 1 pc

The official listed kit weight is approximately 320 g.

Main Functions:

• Supports overhaul of the compressor inlet valve.
• Replaces worn inlet-valve bearings.
• Replaces retaining circlips.
• Replaces the inlet-valve spring.
• Restores smooth valve movement.
• Helps maintain accurate inlet-air control.
• Supports stable compressor capacity control.
• Helps reduce mechanical play and abnormal valve movement.
• Supports reliable oil-free compressor operation.

Inlet Valve Operating Cycle:

1. Air Intake: Atmospheric air reaches the compressor inlet.
2. Valve Control: The inlet valve regulates the quantity of air entering the compressor.
3. Valve Opening: The valve opens as compressor capacity demand increases.
4. Airflow Increase: More atmospheric air enters the compression element.
5. Compression: The compressor element compresses the incoming air.
6. Capacity Reduction: When demand decreases, the inlet valve moves toward a closed position.
7. Airflow Reduction: Less air enters the compression element.
8. Mechanical Support: Bearings provide smooth movement, circlips retain components and the spring maintains the required mechanical force.
9. Continuous Regulation: The valve repeatedly adjusts according to the compressor control system.

Role of the Bearings:

The bearings contained in the kit support smooth movement of the inlet-valve mechanism.

During operation, the valve mechanism repeatedly moves as compressor capacity changes.

A worn bearing may cause:

• Increased mechanical play.
• Rough movement.
• Increased friction.
• Incorrect valve positioning.
• Abnormal noise.
• Reduced control accuracy.

Replacing the bearings during overhaul helps restore smooth and controlled movement.

Role of the Circlips:

The circlips retain the relevant inlet-valve components on their shafts or in their designated positions.

A damaged, weakened or incorrectly installed circlip can allow component movement or loss of correct assembly position.

Replacing the circlips during overhaul helps ensure that the serviced components remain securely positioned.

Role of the Spring:

The spring provides mechanical force within the inlet-valve mechanism.

It assists the valve mechanism in returning toward its required position during changes in compressor operating conditions.

A fatigued or damaged spring may result in:

• Incorrect valve movement.
• Slow valve response.
• Unstable inlet control.
• Incorrect compressor capacity.
• Abnormal operating behavior.

Replacing the spring restores the intended mechanical response of the inlet valve.

Possible Failure Conditions:

The inlet valve and its internal components can deteriorate due to:

• Normal mechanical wear.
• Repeated valve movement.
• Spring fatigue.
• Bearing wear.
• Contamination.
• Incorrect lubrication where applicable.
• Corrosion.
• Excessive mechanical play.
• Incorrect assembly.

Possible compressor symptoms include:

• Unstable compressor capacity.
• Incorrect inlet airflow.
• Reduced compressor performance.
• Difficulty maintaining required pressure.
• Abnormal inlet-valve noise.
• Slow or irregular valve movement.
• Increased energy consumption.
• Compressor control problems.
• Unexpected operating alarms.

Similar symptoms can also be caused by control valves, pneumatic circuits, sensors or other compressor components, so proper diagnosis is required.

Maintenance / Overhaul Procedure:

Before servicing the inlet valve, stop the compressor using the normal shutdown procedure.

Isolate the electrical supply and all applicable pneumatic energy sources.

Completely depressurize the compressor and ensure that stored energy has been safely released.

Allow hot components to cool before beginning mechanical work.

Inspect the inlet-valve assembly for:

• Bearing wear.
• Excessive play.
• Damaged circlips.
• Spring fatigue or damage.
• Corrosion.
• Contamination.
• Damaged valve surfaces.
• Abnormal mechanical wear.

Disassemble the inlet-valve mechanism according to the applicable Atlas Copco service procedure.

Remove the old bearings, circlips and spring.

Clean the relevant components and mating surfaces.

Install the replacement components supplied with the 2906017600 overhaul kit.

During installation:

• Ensure both bearings are correctly positioned.
• Install circlips completely into their retaining grooves.
• Check that circlips are not distorted.
• Install the spring in the correct orientation.
• Ensure the valve mechanism moves freely.
• Check for excessive mechanical play.
• Do not force components into position.
• Verify correct assembly before closing the inlet-valve mechanism.

After reassembly, manually check the valve movement according to the applicable service procedure.

Restart the compressor and monitor:

• Inlet-valve movement.
• Compressor capacity.
• Operating pressure.
• Airflow.
• Compressor temperature.
• Abnormal noise.
• Overall operating stability.

Service Benefits:

Using the Atlas Copco 2906017600 Inlet Valve Overhaul Kit during appropriate maintenance helps:

• Restore inlet-valve mechanical condition.
• Improve valve movement.
• Reduce mechanical play.
• Maintain accurate inlet-air regulation.
• Support stable compressor capacity.
• Reduce the risk of inlet-valve malfunction.
• Maintain reliable compressor operation.
• Reduce the possibility of unplanned downtime.

Part Number: 2906017600
Alternative Number: 2906-0176-00 / 2906 0176 00
Brand: Atlas Copco
Official Description: Inlet Valve Overhaul Kit
Application: ZR/ZT75–90 oil-free compressors
Official Listed Weight: 320 g
Component Type: Inlet-valve overhaul/service kit
Main Components: Bearings, circlips and spring
Primary Function: Restores the mechanical condition of the inlet-valve assembly
Operating Function: Supports smooth and controlled regulation of compressor inlet airflow
Main Benefits: Reliable inlet-air control, smooth valve movement, stable compressor capacity and reduced risk of mechanical failure.

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