Atlas Copco Minimum Pressure Valve (MPV) Service Kit Replacement – 2901141100

Atlas Copco 2901141100 – Minimum Pressure Valve (MPV) Service Kit

The Atlas Copco 2901141100 (2901-1411-00) MPV Kit is a maintenance and repair kit for the Minimum Pressure Valve used in compatible Atlas Copco oil-injected screw compressors. Its primary purpose is to restore the valve’s sealing, spring action and pressure-control performance during compressor servicing.

Atlas Copco’s official catalog identifies the part as “KIT FOR OIL INJECTED SCREW COMPRESSOR” and lists a total weight of 72 g. The official component list includes a seal washer, grease, valve, springs, O-ring and MPV assembly instructions.

Working Process:

During operation of an oil-injected rotary screw compressor, compressed air mixed with oil enters the separator vessel. The compressor requires a controlled minimum internal pressure to maintain proper oil circulation, lubrication, cooling and sealing.

The Minimum Pressure Valve (MPV) is installed in the compressed-air outlet circuit and helps maintain this minimum internal pressure.

During compressor start-up, the MPV remains closed or restricted. This allows pressure to build inside the separator and compressor oil circuit.

When the internal pressure reaches the valve’s specified opening pressure, the pressure acting on the valve overcomes the spring force. The valve then opens progressively, allowing compressed air to flow toward the downstream air system.

During normal loaded operation, the valve remains sufficiently open to permit the required compressed-air flow while maintaining the appropriate internal compressor pressure.

When the compressor unloads or stops, the pressure conditions change and the spring-loaded valve moves toward its closed or restricted position.

This action helps maintain stable internal pressure and limits unwanted reverse airflow from the downstream system.

The 2901141100 MPV Kit provides the service components needed to restore this valve mechanism.

Atlas Copco’s official component list includes:

• Seal Washer – 1 pc
• Tube Grease – 1 pc
• Valve – 1 pc
• Spring – 1 pc
• Spring – 1 pc
• O-ring – 1 pc
• MPV Assembly Instructions – 1 pc

The springs provide the required closing force and determine the pressure response of the valve.

The valve component controls the passage of compressed air from the compressor’s internal pressure circuit toward the downstream system.

The O-ring maintains an airtight seal between mating components and prevents internal or external leakage.

The seal washer provides additional sealing at the applicable connection.

The supplied grease is used during assembly where specified to facilitate correct component installation and movement.

Operating Cycle:

1. Start-up: The MPV restricts the discharge path so internal pressure can build.
2. Pressure build-up: Compressor pressure rises to the required minimum operating level.
3. Opening: Once the required pressure is reached, the MPV opens against spring force.
4. Normal operation: Compressed air flows toward the downstream system while minimum internal pressure is maintained.
5. Unloading/shutdown: Changing pressure conditions allow the spring-loaded valve to move toward the closed/restricted position.

This operating sequence helps maintain proper oil circulation and protects the compressor from operating under unsuitable internal pressure conditions.

Failure Conditions:

With extended operation, springs can weaken, O-rings can harden or become damaged, and the valve can develop contamination or wear.

A damaged O-ring may cause air leakage and prevent the valve from maintaining the required pressure differential.

A weakened spring can change the MPV opening pressure.

If the valve opens too early, the compressor may fail to build sufficient internal pressure during start-up. This can negatively affect oil circulation.

If the valve remains closed or restricted, compressed-air discharge can be limited and internal pressure may become excessive.

If the valve does not close correctly during unloading or shutdown, downstream pressure can move back toward the compressor.

These conditions can lead to unstable pressure, increased energy consumption, poor compressor performance and accelerated wear of compressor components.

Maintenance Procedure:

Before servicing the MPV, the compressor must be stopped, electrically isolated, completely depressurized and allowed to cool according to the applicable Atlas Copco safety procedure.

The MPV should be inspected for:

• Damaged or hardened O-ring
• Weak or damaged springs
• Contamination
• Valve wear
• Leakage
• Incorrect valve movement
• Damaged sealing surfaces

The old service components should be removed carefully without damaging the valve housing.

The components supplied in the 2901141100 MPV Kit should be installed in their specified positions.

All sealing surfaces must be cleaned before assembly.

The O-ring must be installed without twisting, cutting, overstretching or pinching.

The springs must be positioned correctly to provide the specified valve closing force.

The seal washer must be correctly seated.

Grease should be applied only where specified by the applicable Atlas Copco assembly instructions.

After assembly, the valve should move freely without sticking.

The compressor should then be restarted and monitored during start-up, loading, unloading and shutdown.

Internal pressure should build correctly before the MPV allows the required downstream airflow.

The MPV assembly should also be checked for leakage and abnormal pressure behavior.

A correctly serviced MPV maintains the compressor’s minimum internal pressure and supports proper oil circulation and stable compressor operation.

Using the Atlas Copco 2901141100 MPV Kit during the appropriate maintenance operation helps restore valve sealing, spring performance and minimum-pressure control.

Part Number: 2901141100
Alternative Number: 2901-1411-00 / 2901 1411 00
Brand: Atlas Copco
Part Description: MPV Service Kit / Minimum Pressure Valve Kit
Official Description: Kit for Oil-Injected Screw Compressor
Component Type: Minimum Pressure Valve maintenance kit
Official Listed Weight: 72 g
Main Components: Valve, springs, O-ring, seal washer, grease and assembly instructions
Primary Function: Maintains minimum internal compressor pressure
Secondary Function: Controls compressed-air discharge and helps prevent reverse airflow
Operating Function: Restricts discharge during pressure build-up and opens when the required minimum pressure is reached
Main Benefits: Stable internal pressure, reliable oil circulation, improved sealing, controlled discharge flow and dependable compressor operation.

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