Yanmar KSC3 Marine Air Compressor

Yanmar KSC3 Marine High-Pressure Air Compressor

The Yanmar KSC3 (and variation KSC3-V) is a heavy-duty two-stage high pressure reciprocating air compressor made by Yanmar Diesel Engine Co., Ltd. The KSC3 is particularly well adapted to the arduous conditions of naval engine rooms and provides reliable high pressure compressed air at normal outlet pressures up to 30 kgf/cm².

As marine engineers, we rely on the Yanmar KSC3 series for important auxiliary service, such as main propulsion diesel engine starting air receivers, emergency air vessel charging, and heavy-duty deck air operations. Its compact crankcase architecture, great thermal efficiency and water cooled interstage/afterstage design allow continuous duty cycles in extreme tropical room ambient temperature up to 45°C.

Model Details

• Manufacturer: Yanmar Diesel Engine Co., Ltd. (Japan)
• Base Model Series: KSC3
• Variant Models: KSC3-V, KSC3N-T, KSC3-H
• Primary MPN: KSC3
• Secondary Class / Drawings Code: LC309 / 183-90650-1010 / IF6-90650-H000

Key Features

1. Two-Stage Compression Efficiency: Optimizes power transfer while reducing second-stage piston temperature, preventing carbon build-up on delivery valves.
2. Corrosion-Resistant Marine Alloy Valves: High-grade stainless steel concentric ring suction and discharge valves designed for high cycle limits under humid marine conditions.
3. Integrated Interstage & Aftercooler: Rapidly drops air discharge temperature to reduce moisture accumulation before entering the starting air bottles.
4. Low-Maintenance Splash Lubrication: Simple, low-wear oil sump distribution reduces oil pump maintenance downtime and protects big-end bearings.
5. Rugged Cast-Iron Block Construction: Vibration-damped heavy cast frame engineered to meet strict Marine Classification Society standards for engine room installations.

Applications

• Main Marine Diesel Engine Starting Air Supply: Charging 30-bar primary and secondary starting air vessels for commercial vessels, tugboats, and offshore supply vessels.
• Auxiliary Generator Engine Air Starters: Providing quick air delivery to auxiliary generator starter motors.
• Control Air & Pneumatic Utility System Supply: Supplying high-pressure air through reduction stations for pneumatic control valves and shipboard automated systems.
• Emergency Diesel Air Generator Systems: Cold-ship starting equipment configuration integrated with emergency diesel generators.

Compatible Equipment Models & Engine Series

• The Yanmar KSC3 compressor commonly pairs with or serves starting air for the following marine engines and drive motors:
• Yanmar Diesel Propulsion Engines: 6EY18(A)LW, 6EY17W, 6N165-EN, 6HAL2, 6RY17P-GV, 5KDL, 6RL / 6RAL series.
• Auxiliary Generators: Yanmar M-104-1, 6N21 series marine diesel gensets.
• Electric Motor Drives: Standard 5.5 kW / 440V / 60Hz or 380V / 50Hz marine-grade induction motors (IP55/IP56 insulation).

Part Number Cross-References

• Yanmar OEM Part Number: KSC3 / KSC3-V / KSC3N-T
• Outline Drawing Ref: 183-90650-1010
• Fluid Distribution Spec: IF6-90650-H000
• Check Valve Assembly (Discharge): 1S3-90712-3000

Frequently Asked Questions

What viscosity oil should be used in the Yanmar KSC3 compressor crankcase?

Use high-quality SAE 30 or SAE 40 straight mineral or synthetic diesel engine lubricating oil. Maintain oil levels between the min/max marks on the dipstick sight glass and change oil after the initial 50-hour run-in period.

How do I check for suction valve leakage on a KSC3 compressor?

If the 1st stage pressure gauge rises rapidly while overall output capacity drops, inspect the suction and discharge valve plates. Carbon accumulation or broken valve springs will prevent proper seating. Clean the assembly with solvent or lap the valve plates flat.

Can the Yanmar KSC3 be driven by a belt drive configuration?

Yes, the KSC3 can be driven via direct flexible coupling or heavy-duty industrial V-belt pulleys. Ensure correct belt tension and check for cocking or angular misalignment prior to startup.