Atlas Copco Minimum Pressure Valve (MPV) Kit Replacement – 2205490597

Atlas Copco 2205490597 – Minimum Pressure Valve (MPV) Kit

The Atlas Copco 2205490597 (2205-4905-97) Minimum Pressure Valve Kit is a service and maintenance kit used in rotary screw compressor systems. The Minimum Pressure Valve (MPV) controls compressed-air discharge from the separator vessel and maintains the minimum internal pressure required for proper compressor operation.

Working Process:

During compressor start-up, the MPV remains closed or partially restricted. This allows pressure to build inside the oil separator vessel and compressor circuit before compressed air is delivered to the downstream air system.

As the internal pressure increases and reaches the valve’s required opening pressure, the MPV opens and allows compressed air to flow toward the downstream air network. The valve regulates the discharge path while maintaining sufficient pressure inside the compressor.

Maintaining minimum internal pressure is important in an oil-injected screw compressor because the pressure difference assists the circulation of lubricating oil through the compressor air end. The oil provides cooling, lubrication, and sealing for the screw element.

During normal loaded operation, the MPV remains open while helping prevent the internal separator pressure from dropping below the required minimum level. This supports stable oil circulation and efficient air/oil separation.

When the compressor unloads or stops, the MPV closes or restricts the passage. This helps prevent downstream compressed air from flowing backward into the compressor circuit and maintains proper pressure separation during shutdown.

The 2205490597 kit is used to restore the valve’s pressure-control and sealing performance when its internal components become worn, contaminated, or damaged. The part is identified by multiple compressor-parts references as an MPV Kit / Minimum Pressure Valve Kit for Atlas Copco compressors.

During maintenance, the compressor should be stopped, isolated, and completely depressurized before the MPV assembly is serviced. The valve should be dismantled according to the applicable service procedure, and its internal components, spring mechanism, sealing surfaces, and passages should be inspected for wear, contamination, and damage.

The replacement components from the 2205490597 service kit are then installed in the correct position and orientation. Proper sealing is essential to maintain the specified minimum pressure and prevent unwanted air leakage.

After reassembly, the compressor should be tested through its complete start-up, loading, unloading, and shutdown sequence. The MPV should build internal pressure during start-up, open correctly at the required pressure, maintain stable operation, and close effectively during unloading or shutdown.

A worn or malfunctioning MPV can cause slow pressure build-up, unstable discharge pressure, excessive oil carryover, poor oil circulation, reverse airflow, increased power consumption, or starting difficulties.

Correct maintenance of the 2205490597 Minimum Pressure Valve Kit helps maintain minimum internal pressure, support proper oil circulation and air/oil separation, prevent reverse airflow, and ensure reliable and efficient compressor operation.

Part Number: 2205490597
Alternative Number: 2205-4905-97 / 2205 4905 97
Brand: Atlas Copco / Chicago Pneumatic
Part Description: MPV Kit / Minimum Pressure Valve Kit
Component Type: Minimum-pressure and check-valve service kit
Application: Rotary screw air compressors
Primary Function: Maintains minimum internal compressor pressure and controls compressed-air discharge
Secondary Function: Helps prevent reverse compressed-air flow
Main Benefits: Stable pressure, proper oil circulation, effective air/oil separation, reliable starting, and efficient compressor operation.

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