Atlas Copco Minimum Pressure Valve (MPV) Replacement – 1513040081

Atlas Copco 1513040081 – Minimum Pressure Valve (MPV)

The Atlas Copco 1513040081 (1513-0400-81) Minimum Pressure Valve is a pressure-control and non-return valve used in oil-injected screw compressor systems. Its primary function is to maintain the required minimum pressure inside the compressor’s separator circuit while allowing compressed air to flow toward the downstream air network.

Working Process:
When the compressor starts, the Minimum Pressure Valve remains closed or substantially restricted. This allows pressure to build rapidly inside the separator vessel and internal compressor circuit.

Once the internal pressure reaches the valve’s specified opening pressure, the MPV begins to open. Compressed air can then flow from the separator vessel toward the aftercooler and downstream compressed-air system.

Maintaining minimum internal pressure is important in an oil-injected screw compressor because the pressure difference helps circulate oil through the compressor element. The oil provides cooling, lubrication, and sealing during the compression process. Proper MPV operation therefore supports stable temperature, lubrication, and air/oil separation.

During normal operation, the valve regulates airflow according to the pressure difference between the compressor’s internal circuit and the downstream system. It prevents the internal pressure from falling below the required minimum level while still allowing compressed air to be delivered efficiently.

The valve also performs a non-return function. When the compressor unloads or stops and downstream pressure becomes higher than the internal compressor pressure, the valve closes to help prevent compressed air from flowing backward into the compressor.

The 1513040081 MPV contains a piston, M32 seal washer, MPV housing, valve, two springs, and an O-ring. Atlas Copco lists the complete valve weight as 410 g.

During maintenance, the compressor should be stopped, isolated, and completely depressurized before the MPV is removed. The valve, piston, springs, seals, and O-ring should be inspected for wear, contamination, damage, and loss of sealing performance.

If the MPV becomes worn or stuck, the compressor may experience slow pressure build-up, poor oil circulation, excessive oil carryover, pressure instability, reverse airflow, or starting problems.

After servicing or replacement, the valve should be checked for correct opening pressure, closing action, and leakage. Proper operation restores minimum-pressure control and reliable one-way airflow through the compressor system.

Part Number: 1513040081
Alternative Number: 1513-0400-81 / 1513 0400 81
Part Description: Minimum Pressure Valve (MPV)
Brand: Atlas Copco
Application: Oil-injected screw compressors
Component Type: Minimum pressure and non-return valve
Official Listed Weight: 410 g
Primary Function: Maintains minimum internal compressor pressure and prevents reverse airflow
Main Benefits: Supports oil circulation, air/oil separation, pressure stability, efficient operation, and reliable compressor performance.

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