Atlas Copco Oil Stop Valve / Check Valve Kit Replacement – 2901196000

Atlas Copco 2901196000 – Oil Stop Valve / Check Valve Kit

The Atlas Copco 2901196000 (2901-1960-00) Oil Stop Valve / Check Valve Kit is a service kit designed for compatible oil-injected rotary screw compressors. Its main purpose is to control oil flow and prevent unwanted reverse flow within the compressor oil circuit during normal operation, unloading, and shutdown.

Working Process:

During normal compressor operation, the screw air end requires a continuous supply of compressor oil for lubrication, cooling, sealing, and reliable compression. Oil circulates through the compressor oil circuit while the compressed air/oil mixture is processed through the separator system.

The oil-stop valve and check valve assembly controls the direction and availability of oil flow. When the compressor is operating, the pressure difference in the circuit acts on the valve and piston mechanism, allowing the required oil to circulate toward the air end.

The check valve permits flow in the intended direction while restricting reverse flow. This helps maintain the correct oil circulation path and prevents oil from moving backward through the circuit.

The oil-stop valve works together with the spring and piston assembly. During normal operation, compressor pressure overcomes the closing force of the spring and places the valve in the operating position, allowing the required oil flow.

When the compressor unloads or stops, the pressure conditions change. The spring force moves the oil-stop valve toward its closed position. This restricts the oil passage and prevents excessive oil from migrating into the compressor air end.

The closing action is especially important during shutdown. Without effective oil-stop control, oil can drain or migrate into the air end, potentially causing excessive oil accumulation, difficult starting, increased oil carryover, or abnormal compressor operation.

Atlas Copco’s official catalog identifies 2901196000 as “KIT OIL STOP VLV / CHECK VLV FOR OIL INJECTED SCREW COMPRESSOR.” The official product information specifies a kit weight of 600 g.

The official component list includes:

• Check valve – 1 pc
• O-ring 12.3 × 2.4 – 1 pc
• Gasket – 1 pc
• Instrument assembly – 1 pc
• Spring – 1 pc
• Plug G 1/4 A – 1 pc
• O-ring 49.5 × 3 – 1 pc
• Hex socket screw M8 × 85 × 12.9 – 4 pcs
• Oil-stop valve spring – 1 pc
• Oil-stop valve – 1 pc
• O-ring 32.2 × 3 – 1 pc
• Piston – 1 pc

These components work together to provide controlled oil flow, one-way flow protection, spring-assisted closing, and reliable sealing.

The oil-stop valve controls the oil passage during compressor shutdown and unloading. The check valve prevents reverse flow. The piston transfers the pressure force required for valve operation, while the springs provide the necessary return and closing forces.

The O-rings and gasket provide leak-resistant sealing between the valve assembly and compressor housing. The plug and mounting screws secure the assembly and maintain the required mechanical connection.

During continuous compressor operation, the valve assembly is exposed to hot compressor oil, pressure fluctuations, vibration, temperature changes, contamination, and repeated opening and closing cycles.

Over time, the O-rings may harden or deteriorate, springs may lose their original force, and the valve or piston may become contaminated or worn.

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

A defective check valve may allow reverse oil flow or pressure migration through the circuit. This can disturb the intended oil-flow direction and reduce the effectiveness of the oil-control system.

If the valve becomes restricted or fails to open correctly during compressor operation, insufficient oil may reach the air end. Reduced oil circulation can negatively affect rotor lubrication, cooling, and sealing.

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, piston, springs, check valve, O-rings, gasket, and sealing surfaces should be inspected for wear, contamination, corrosion, deformation, and leakage.

The worn components should be replaced using the 2901196000 Oil Stop Valve / Check Valve Kit. O-rings must be installed carefully without twisting, cutting, or damaging their sealing surfaces. Springs, piston, check valve, and oil-stop valve must be installed in the correct positions and orientations 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 oil-stop valve should allow the required oil circulation during compressor operation and close correctly when the compressor unloads or stops. The check valve should prevent unwanted reverse flow.

Correct operation of this assembly helps maintain proper oil circulation during compressor operation while preventing excessive oil migration during shutdown.

Using the Atlas Copco 2901196000 Oil Stop Valve / Check Valve Kit during scheduled maintenance helps restore oil-flow control, reliable sealing, reverse-flow protection, proper shutdown behavior, and dependable compressor performance.

Part Number: 2901196000
Alternative Number: 2901-1960-00 / 2901 1960 00
Brand: Atlas Copco
Part Description: Oil Stop Valve / Check Valve Kit
Official Description: Kit Oil Stop Valve / Check Valve for Oil-Injected Screw Compressor
Component Type: Oil-stop and check-valve service kit
Application: Oil-injected rotary screw compressors
Official Listed Weight: 600 g
Primary Function: Controls oil flow and prevents unwanted reverse flow
Secondary Function: Prevents excessive oil migration into the air end during shutdown
Main Components: Oil-stop valve, check valve, piston, springs, O-rings, gasket, instrument assembly, plug, and mounting screws
Operating Function: Permits controlled oil circulation during operation and restricts reverse oil flow during unloading/shutdown
Main Benefits: Proper lubrication, reduced oil migration, reliable shutdown, improved sealing, reverse-flow protection, and dependable compressor operation.

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