Atlas Copco Oil Stop / Check Valve Kit Replacement – 2901083500

Atlas Copco 2901083500 – Oil Stop / Check Valve Kit

The Atlas Copco 2901083500 (2901-0835-00) Oil Stop/Check Valve Kit is a service kit used in compatible Atlas Copco oil-injected rotary screw compressor systems. Its main purpose is to control oil flow and prevent unwanted reverse flow within the compressor oil circuit, particularly during unloading and compressor shutdown.

Working Process:

During normal compressor operation, the screw air end requires a continuous supply of compressor oil for lubrication, cooling, sealing, and efficient operation. Oil circulates through the compressor oil circuit and is returned for reuse after passing through the appropriate separation and filtration components.

The oil-stop/check-valve assembly controls this oil circulation. When the compressor is operating, the pressure difference in the oil circuit allows the valve to open and permits the required oil flow toward the compressor air end.

As the compressor operates under load, oil continuously reaches the air end. It absorbs heat generated during compression, lubricates the rotating screw components, and assists in sealing the internal compression clearances.

When the compressor unloads or stops, the pressure conditions inside the oil circuit change. The valve mechanism moves toward the closed position, restricting the oil passage.

This prevents excessive oil from flowing or draining toward the air end when the compressor is not operating.

The check-valve function also prevents unwanted reverse flow. This helps maintain the correct oil level and pressure conditions within the compressor circuit and reduces the possibility of oil migration into the air end during shutdown.

Atlas Copco’s official parts page identifies 2901083500 as “OILSTOP/CHECKVALVE KIT.” The part is also listed by spare-parts suppliers under the description Oil Stop/Check Valve Kit and OEM number 2901 0835 00.

The kit is designed to restore the operating condition of the oil-stop and check-valve assembly. The valve mechanism controls flow, while the sealing elements maintain a leak-resistant connection between the valve components and compressor housing.

During normal compressor service, the valve components are exposed to hot compressor oil, pressure fluctuations, vibration, temperature changes, and repeated opening and closing cycles. Over time, the valve and sealing components may become worn, contaminated, hardened, or damaged.

A defective oil-stop/check valve may fail to close correctly after shutdown. This can allow oil to migrate into the compressor air end, potentially resulting in excessive oil accumulation, increased oil carryover, difficult starting, abnormal compressor operation, or increased oil consumption.

If the valve becomes restricted or fails to open correctly during operation, the oil supply to the air end may be reduced. Insufficient oil circulation can negatively affect lubrication, cooling, and sealing of the screw element.

During maintenance, the compressor must be stopped, electrically isolated, completely depressurized, and allowed to cool before the oil-stop/check-valve assembly is serviced.

The valve body, internal valve components, springs, seals, O-rings, and mating surfaces should be inspected for contamination, wear, corrosion, deformation, and leakage.

The worn components should be replaced using the 2901083500 Oil Stop/Check Valve Kit. Sealing components must be installed correctly without twisting, cutting, or damaging them. The valve components should be installed in the correct orientation according to the applicable Atlas Copco service procedure.

After reassembly, the compressor should be checked for oil and air leakage. The compressor should then be operated through its start-up, loading, unloading, and shutdown cycles.

During testing, the valve should allow the required oil flow during compressor operation and close effectively when the compressor unloads or stops.

Correct operation of the oil-stop/check valve helps maintain proper oil circulation during operation while preventing unwanted oil migration during shutdown.

Using the Atlas Copco 2901083500 Oil Stop/Check Valve Kit during appropriate maintenance helps restore oil-flow control, prevent reverse oil flow, reduce oil migration, protect the compressor air end, and maintain reliable compressor performance.

Part Number: 2901083500
Alternative Number: 2901-0835-00 / 2901 0835 00
Brand: Atlas Copco
Part Description: Oil Stop / Check Valve Kit
Official Description: OILSTOP/CHECKVALVE KIT
Component Type: Oil-stop and non-return valve service kit
Application: Atlas Copco oil-injected rotary screw compressors
Primary Function: Controls oil flow and prevents unwanted reverse flow
Operating Function: Allows oil circulation during operation and restricts oil migration during unloading/shutdown
Maintenance Function: Restores valve movement and sealing performance
Main Benefits: Proper oil circulation, reduced oil migration, improved shutdown protection, reduced leakage, 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.