Atlas Copco Oil Stop Valve Kit Replacement – 2205519788

Atlas Copco 2205519788 – Oil Stop Valve Kit / LU90 OSV

The Atlas Copco 2205519788 (2205-5197-88) Oil Stop Valve Kit, also identified in parts references as LU90 OSV, is a service and replacement kit used in compatible Atlas Copco oil-injected screw compressor systems. Its primary function is to control compressor oil flow and prevent unwanted oil migration into the compressor air end during unloading and shutdown.

Working Process:

During normal compressor operation, lubricating oil is supplied to the screw air end for cooling, lubrication, sealing, and efficient compression. The oil circulates through the compressor oil circuit under controlled pressure.

The Oil Stop Valve (OSV) regulates the oil passage to the air end. When the compressor is running, the pressure in the oil circuit acts on the valve mechanism and keeps the oil passage in its operating position, allowing the required oil flow.

The circulating oil lubricates the rotating screw components, removes heat generated during compression, and assists in sealing the clearances between the screw rotors.

When the compressor unloads or stops, the pressure conditions in the oil circuit change. The valve mechanism moves toward its closed position and restricts the oil passage.

This prevents excessive oil from draining or migrating into the air end while the compressor is stopped. Controlling oil migration helps reduce the possibility of oil accumulation, difficult starting, excessive oil carryover, and abnormal compressor operation.

Available parts references directly identify 2205519788 as an Oil Stop Valve Kit, while another Atlas Copco parts listing identifies it as LU90 OSV.

The valve assembly operates through pressure-assisted movement. During compressor operation, oil pressure positions the valve to permit the required oil circulation. When pressure decreases during unloading or shutdown, the internal closing mechanism restricts the oil passage.

The kit is intended to restore the valve’s oil-flow control and sealing performance when the original valve assembly becomes worn or defective.

During service, the Oil Stop Valve is exposed to hot compressor oil, pressure fluctuations, vibration, temperature changes, contamination, and repeated loading/unloading cycles.

Over time, the valve mechanism and sealing components can wear or deteriorate. Contamination may also restrict valve movement.

A defective Oil Stop Valve may remain partially open after compressor shutdown. This can allow excessive oil to migrate into the air end and may result in increased oil consumption, oil carryover, difficult starting, or abnormal compressor operation.

If the valve becomes restricted during normal operation, the required oil supply to the air end may be reduced. Insufficient oil circulation can negatively affect lubrication, cooling, and rotor sealing.

Maintenance Procedure:

Before servicing the Oil Stop Valve, the compressor must be stopped, electrically isolated, completely depressurized, and allowed to cool.

The existing valve assembly should be removed according to the applicable Atlas Copco service procedure. The valve mechanism, spring/actuating components, sealing surfaces, and oil passages should be inspected for wear, contamination, corrosion, deformation, and leakage.

The defective components should be replaced using the 2205519788 Oil Stop Valve Kit.

All sealing components must be installed correctly without twisting, cutting, or damaging their sealing surfaces. The valve assembly must be installed in the correct position and orientation.

After installation, the compressor should be checked for oil leakage and correct valve movement.

The compressor should then be operated through its start-up, loaded, unloaded, and shutdown cycles.

During testing, the Oil Stop Valve should permit the required oil circulation during normal compressor operation and restrict the oil passage correctly when the compressor unloads or stops.

Correct operation of the Oil Stop Valve maintains proper oil circulation during compressor operation while reducing unwanted oil migration during shutdown.

Using the Atlas Copco 2205519788 Oil Stop Valve Kit during appropriate maintenance helps restore oil-flow control, reduce oil migration, improve shutdown behavior, protect the compressor air end, and maintain reliable compressor performance.

Part Number: 2205519788
Alternative Number: 2205-5197-88 / 2205 5197 88
Brand: Atlas Copco
Part Description: Oil Stop Valve Kit
Related Designation: LU90 OSV
Component Type: Oil-stop valve service kit
Application: Compatible Atlas Copco oil-injected screw compressors
Primary Function: Controls oil flow to the compressor air end
Secondary Function: Prevents excessive oil migration during unloading and shutdown
Operating Function: Allows controlled oil circulation during operation and restricts oil flow when the compressor stops
Main Benefits: Proper lubrication, cooling, sealing, reduced oil migration, improved starting reliability, reduced oil carryover, 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.