Atlas Copco MPV / Minimum Pressure Valve Kit Replacement – 1625005540

Atlas Copco 1625005540 – MPV / Minimum Pressure Valve Kit

The Atlas Copco 1625005540 (1625-0055-40) MPV Kit is a service and replacement kit for a Minimum Pressure Valve (MPV) assembly. Atlas Copco’s official catalog identifies the product as “MPV KIT FOR MEDICAL EQUIPMENT” and lists a weight of 3.06 kg.

Working Process:

The Minimum Pressure Valve maintains the required minimum pressure inside the compressor’s oil separator or pressure vessel during operation.

When the compressor starts, the MPV remains sufficiently closed to allow pressure to build within the compressor system. Maintaining this minimum pressure is important for proper oil circulation and for ensuring that the oil-injected compressor operates under the intended pressure conditions.

Once the internal pressure reaches the valve’s opening pressure, the MPV progressively opens and allows compressed air to flow toward the downstream air network.

During normal operation, the valve regulates the transition between the compressor’s internal pressure and the downstream system pressure.

The 1625005540 MPV Kit contains the replacement components required to restore the mechanical and sealing condition of the minimum pressure valve.

Atlas Copco’s official component list includes:

• Piston – 1 pc
• Instrument Assembly – 1 pc
• Spring – 1 pc
• Piston – 1 pc
• Spring – 1 pc
• O-ring – 1 pc
• Seal – 1 pc
• O-ring 26.7 × 1.78 – 1 pc
• Instruction for Assembly of MPV – 1 pc
• Assembly Valve – 1 pc

The pistons move in response to pressure differences and provide the mechanical movement required for valve regulation.

The springs provide the closing force that keeps the valve in its required position until the appropriate pressure is reached.

The O-rings and seal maintain a leak-tight interface between the moving and stationary components. Proper sealing is essential for accurate pressure control.

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

During compressor start-up, the MPV helps the compressor build the required internal pressure before allowing unrestricted discharge flow.

Once the required minimum pressure is reached, the valve opens and compressed air can flow to the air receiver or downstream distribution system.

When downstream pressure becomes high or the compressor unloads, the valve responds to the changing pressure conditions and restricts flow as required.

A correctly functioning MPV therefore helps maintain stable compressor pressure, reliable oil circulation and correct compressor operating conditions.

Possible Failure Conditions:

With continuous operation, the piston, springs, seals and O-rings can experience wear, fatigue, deformation and loss of elasticity.

A worn or damaged piston may cause sticking or inaccurate valve movement.

A weak spring can change the valve’s opening or closing characteristics.

Damaged O-rings or seals can cause internal or external leakage and prevent the MPV from maintaining the required pressure.

If the MPV opens too early, the compressor may not build sufficient internal pressure during start-up. This can negatively affect oil circulation and compressor operation.

If the MPV fails to open correctly, excessive internal pressure may develop and the compressor may experience restricted discharge flow.

Incorrect MPV operation can therefore result in unstable pressure, poor compressor performance, increased energy consumption or abnormal operating conditions.

Maintenance Procedure:

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

The MPV assembly should be inspected for contamination, piston wear, damaged springs, deteriorated O-rings, damaged seals and abnormal valve movement.

The old sealing and worn components should be removed carefully.

The components supplied in the 1625005540 MPV Kit should be installed in their correct positions and orientations.

The piston must move freely without binding.

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

Springs must be correctly positioned so that the specified closing force is maintained.

The valve assembly must be correctly seated and secured.

After assembly, the MPV should be checked for smooth movement and correct sealing.

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

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

The valve should open smoothly at the appropriate operating pressure and maintain stable pressure during normal compressor operation.

The system should also be inspected for air leakage around the MPV assembly.

Using the Atlas Copco 1625005540 MPV Kit during the appropriate maintenance operation helps restore minimum-pressure control, valve sealing, pressure stability and reliable compressor operation.

Part Number: 1625005540
Alternative Number: 1625-0055-40 / 1625 0055 40
Brand: Atlas Copco
Part Description: MPV Kit / Minimum Pressure Valve Kit
Official Description: MPV Kit for Medical Equipment
Component Type: Minimum Pressure Valve service kit
Official Listed Weight: 3.06 kg
Main Components: Pistons, springs, valve assembly, O-rings, seal and instrument assembly
Primary Function: Maintains minimum compressor internal pressure
Secondary Function: Controls compressed-air discharge toward the downstream system
Operating Function: Remains closed/restricted during pressure build-up and opens when the required minimum pressure is achieved
Main Benefits: Stable minimum pressure, reliable oil circulation, controlled air discharge, improved valve sealing and dependable 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.