Atlas Copco Oil Demister Service Kit Replacement – 2906904500

Atlas Copco 2906904500 – Oil Demister Service Kit

The Atlas Copco 2906904500 (2906-9045-00) is an Oil Demister Service Kit designed for compatible Atlas Copco oil-free turbo compressors, including applicable ZH-series equipment.

The oil demister is an important component of the compressor’s oil-management system. Its primary purpose is to separate fine oil mist from the air or gas stream associated with the compressor’s lubrication system, preventing excessive oil carry-over and helping maintain clean operation of downstream components.

The official Atlas Copco catalog lists the kit weight as approximately 3.08 kg and specifies a demister element with three O-rings as the kit components.

Working Process:

During compressor operation, the turbo compressor generates compressed air through high-speed rotating compression stages.

Although the compression process is oil-free on the compressed-air side, certain compressor assemblies can contain lubricated bearings, gears or associated lubrication circuits.

The lubrication system uses oil to protect these mechanical components from wear and to remove heat generated during operation.

Fine oil mist can be generated as a result of high-speed rotating components and oil circulation.

This oil-laden air or ventilation stream is directed toward the oil demister.

Inside the demister, the specially designed filter element captures fine oil droplets and causes them to combine into larger droplets.

The larger oil droplets can then separate from the airflow and return to the applicable oil-management circuit.

The cleaned air continues through the appropriate outlet or ventilation path.

This continuous separation process helps reduce oil carry-over and protects surrounding and downstream equipment from oil contamination.

Main Functions:

• Separates fine oil mist from the applicable air stream.
• Reduces oil carry-over.
• Helps return separated oil to the lubrication system.
• Protects downstream components from oil contamination.
• Supports efficient lubrication-system operation.
• Helps maintain clean ventilation/airflow.
• Supports reliable turbo-compressor operation.
• Helps maintain the service condition of the compressor.

Official Kit Components:

Atlas Copco’s official product listing specifies:

• Demister Element – 1 pc
• O-ring – 2 pcs
• O-ring – 1 pc

The complete kit weight is approximately 3.08 kg.

Oil Demister Operating Cycle:

1. Lubrication: Oil circulates through the applicable lubricated compressor components.
2. Oil Mist Formation: High-speed operation can produce fine oil droplets or mist.
3. Oil-Mist Flow: The oil-containing stream moves toward the demister.
4. Filtration: The demister element captures fine oil droplets.
5. Coalescence: Small droplets combine into larger droplets on the demister medium.
6. Oil Separation: Larger droplets separate from the airflow.
7. Oil Recovery: Separated oil returns to the applicable oil circuit.
8. Clean-Air Passage: The cleaned stream continues through the designated outlet.
9. Continuous Operation: The process continues while the compressor is operating.

Role of the Demister Element:

The demister element is the primary oil-separation component in the service kit.

Its filtering/coalescing structure provides a large surface area for capturing fine oil droplets.

As oil mist passes through the element:

• Fine droplets are captured.
• Droplets combine into larger droplets.
• Larger droplets drain away.
• Oil carry-over is reduced.
• The downstream air/ventilation stream becomes cleaner.

Over time, the demister element can become contaminated or saturated with oil and may develop increased pressure resistance.

Replacing the element during scheduled maintenance helps restore effective oil-mist separation.

Role of the O-Rings:

The three O-rings supplied with the kit provide sealing at the demister assembly.

They prevent unwanted leakage around the demister housing and associated connections.

Over time, O-rings can experience:

• Hardening
• Compression set
• Loss of elasticity
• Cracking
• Surface damage
• Thermal ageing

Replacing the O-rings together with the demister element helps restore the sealing integrity of the serviced assembly.

Importance of Oil Demisting:

Effective oil-mist separation is important for maintaining the cleanliness and reliability of the compressor system.

If the demister becomes saturated, damaged or restricted, possible effects include:

• Increased oil carry-over.
• Oil contamination of downstream areas.
• Increased pressure drop.
• Reduced ventilation performance.
• Increased oil consumption.
• Oil accumulation around outlets or connections.
• Reduced compressor reliability.

A contaminated demister can also increase the load on the lubrication/ventilation circuit.

Possible Failure Conditions:

The demister assembly may deteriorate because of:

• Normal operating hours.
• Oil contamination.
• Filter saturation.
• High operating temperature.
• Pressure fluctuations.
• Incorrect installation.
• Damaged sealing components.
• Excessive oil carry-over.
• Contamination.

Possible symptoms include:

• Increased oil mist at the outlet.
• Oil accumulation around the demister housing.
• Increased pressure drop.
• Increased oil consumption.
• Reduced ventilation flow.
• Oil contamination of surrounding components.
• Abnormal compressor operating conditions.

These symptoms should be diagnosed carefully because oil carry-over can also originate from excessive oil level, lubrication-system problems, damaged seals or other components.

Maintenance Procedure:

Before servicing the oil demister, stop the compressor according to the normal shutdown procedure.

Isolate the electrical supply and applicable pneumatic or process energy sources.

Allow the equipment to cool to a safe service temperature.

Ensure the applicable circuit is depressurized before opening the demister assembly.

Inspect the demister housing and surrounding components for:

• Oil accumulation.
• Leakage.
• Contamination.
• Damaged sealing surfaces.
• Damaged O-rings.
• Corrosion.
• Mechanical damage.

Remove the old demister element carefully.

Remove the existing O-rings.

Clean the relevant sealing surfaces and demister housing.

Install the new 2906904500 Oil Demister Service Kit.

During installation:

• Ensure the demister element is correctly positioned.
• Install all three O-rings in their correct locations.
• Ensure O-rings are not twisted, cut or damaged.
• Clean all mating surfaces.
• Ensure the demister housing is correctly assembled.
• Secure all applicable connections correctly.
• Prevent foreign material from entering the lubrication/ventilation circuit.

After assembly, perform the applicable leak and functional checks.

Restart the compressor according to the manufacturer’s operating procedure.

Monitor:

• Oil carry-over.
• Ventilation/airflow.
• Pressure drop.
• Oil level.
• Oil leakage.
• Demister housing condition.
• Compressor operating temperature.
• Overall compressor performance.

Service Benefits:

Using the Atlas Copco 2906904500 Oil Demister Service Kit during appropriate maintenance helps:

• Restore oil-mist separation performance.
• Reduce oil carry-over.
• Maintain clean airflow/ventilation.
• Protect downstream components.
• Restore demister sealing.
• Reduce contamination.
• Support proper lubrication-system operation.
• Maintain reliable turbo-compressor performance.
• Reduce the risk of unexpected downtime.

Part Number: 2906904500
Alternative Number: 2906-9045-00 / 2906 9045 00
Brand: Atlas Copco
Official Description: Oil Demister Service Kit for Oil-Free Turbo Compressors
Application: Compatible stationary oil-free turbo compressors, including applicable ZH-series equipment
Official Listed Weight: 3.08 kg
Kit Type: Oil demister service/maintenance kit
Main Components: 1 demister element + 3 O-rings
Primary Function: Separation of fine oil mist from the applicable air/ventilation stream
Operating Function: Captures and coalesces fine oil droplets so separated oil can be recovered while cleaner air continues through the system
Main Benefits: Reduced oil carry-over, cleaner airflow, improved lubrication-system performance and reliable compressor operation.

Disclaimer: All manufacturer names, trademarks, model numbers, and part numbers are used solely for identification and compatibility purposes. Our products are high-quality aftermarket replacement products and are not manufactured, sponsored, endorsed, or authorized by the original equipment manufacturer (OEM). All trademarks remain the property of their respective owners.