Atlas Copco Minimum Pressure Valve (MPV) Kit Replacement – 3001500626

Atlas Copco 3001500626 – Minimum Pressure Valve (MPV) Kit

The Atlas Copco 3001500626 (3001-5006-26) is a Minimum Pressure Valve (MPV) service kit used to restore the pressure-control and sealing performance of the compressor’s minimum pressure valve assembly.

The MPV is an important component in an oil-injected screw compressor. It maintains the required minimum internal pressure within the compressor’s air/oil separator circuit and controls the flow of compressed air toward the downstream air system.

Working Process:

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

Maintaining sufficient internal pressure is important for proper oil separation, oil circulation, lubrication and cooling.

When the compressor reaches the required minimum internal pressure, the pressure acting on the MPV overcomes its closing force. The valve then opens and allows compressed air to flow toward the aftercooler and downstream compressed-air network.

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

When the compressor unloads or stops, the pressure conditions change and the valve moves toward the closed or restricted position. This helps reduce reverse airflow from the downstream system toward the compressor.

The 3001500626 MPV Kit is used during maintenance when the MPV’s internal sealing or mechanical components require replacement.

Available parts references identify the kit as 3001 5006 26 – MPV KIT. One parts reference lists the kit together with an O-ring, nut, washer and set screws.

Main Kit Components Referenced:

• Minimum Pressure Valve Kit – 1 pc
• O-ring – 1 pc
• Nut – 1 pc
• Washer – 1 pc
• Set Screw – 3 pcs

These components restore the valve’s sealing, positioning and mechanical fastening.

The O-ring provides a leak-resistant seal between the valve and its mating surface. A properly sealed MPV is essential for maintaining the pressure differential required for correct valve operation.

The nut, washer and set screws secure the relevant valve components and help prevent movement caused by continuous compressor vibration.

Operating Cycle:

1. Start-up: The MPV restricts the compressed-air outlet.
2. Pressure Build-up: Internal separator pressure increases.
3. Minimum Pressure Reached: Pressure force becomes sufficient to open the valve.
4. Valve Opening: Compressed air begins flowing toward the downstream system.
5. Normal Operation: The MPV allows controlled airflow while maintaining suitable internal pressure.
6. Unloading/Shutdown: The valve restricts flow and helps limit reverse airflow.

This sequence helps the compressor maintain the pressure conditions required for reliable operation.

Importance of the MPV:

The MPV helps maintain the pressure difference required for effective oil circulation and separation in oil-injected screw compressors.

If minimum internal pressure is too low, oil circulation and separation can be negatively affected.

If the MPV remains excessively closed, compressed-air discharge can become restricted and internal pressure may increase abnormally.

If the MPV opens too early, the compressor may not build sufficient pressure during start-up.

If the valve does not close properly during unloading or shutdown, downstream pressure may flow back toward the compressor.

Possible Failure Conditions:

With prolonged operation, MPV components can experience wear, contamination, vibration-related loosening and seal deterioration.

Typical symptoms of MPV problems can include:

• Slow or incorrect pressure build-up
• Air leakage around the valve
• Unstable compressor pressure
• Restricted compressed-air discharge
• Reverse airflow during unloading
• Increased energy consumption
• Poor compressor performance
• Abnormal oil circulation or separation

A damaged O-ring can cause internal or external leakage.

Loose or damaged fastening components can affect valve positioning and lead to unreliable operation.

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 assembly should be inspected for:

• O-ring deterioration
• Valve wear
• Contamination
• Loose fastening components
• Damaged threads
• Air leakage
• Abnormal valve movement

The existing worn components should be removed carefully without damaging the valve body or mating surfaces.

The 3001500626 MPV Kit should be installed according to the applicable Atlas Copco service instructions.

All sealing surfaces must be thoroughly cleaned before assembly.

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

The washer, nut and set screws must be correctly positioned and secured.

After assembly, the valve should be checked for correct seating and unrestricted movement.

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

The technician should verify correct pressure build-up, stable discharge pressure and absence of leakage around the MPV assembly.

A properly serviced MPV maintains stable internal compressor pressure and allows controlled compressed-air delivery to the downstream system.

Using the Atlas Copco 3001500626 MPV Kit during the appropriate maintenance operation helps restore pressure regulation, sealing performance, mechanical security and reliable compressor operation.

Part Number: 3001500626
Alternative Number: 3001-5006-26 / 3001 5006 26
Brand: Atlas Copco
Part Description: MPV Kit / Minimum Pressure Valve Service Kit
Component Type: Minimum Pressure Valve maintenance kit
Known Application Reference: Atlas Copco GA110/GA132 applications
Main Components Referenced: MPV kit, O-ring, nut, washer and set screws
Primary Function: Maintains minimum internal compressor pressure
Secondary Function: Controls compressed-air discharge and helps limit reverse airflow
Operating Function: Restricts discharge during pressure build-up and opens after the required minimum pressure is achieved
Main Benefits: Stable pressure control, reliable oil circulation, reduced leakage, secure valve assembly and dependable compressor operation.

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