The kit for the pressure valve, code P51731-04, provides the necessary parts to overhaul or replace the pressure-control valve within the MAN L21/31 engine’s lubrication or fuel system. The pressure valve regulates system pressure, ensuring stable operating conditions, protecting sensitive components, and maintaining optimal flow rates. Over time, valve components may wear or lose calibration due to vibration, thermal stress, or contaminant exposure. This renewal kit restores precise pressure regulation, safeguarding engine performance, preventing lubrication failures, and supporting long-term operational stability in demanding marine and stationary engine environments.

The kit for renewal of piston rings, code P51706-03, provides all essential components needed to restore optimal sealing and compression performance in the MAN L21/31 engine. Piston rings are critical for maintaining combustion efficiency, regulating oil consumption, and ensuring proper heat transfer from the piston to the cylinder liner. Over time, rings wear due to high pressure and thermal cycling, and this renewal kit ensures a complete and precise replacement process. By restoring tight sealing and reducing blow-by, the kit contributes to improved engine efficiency, lower emissions, and extended service life—an indispensable maintenance solution for engines operating under heavy marine or industrial loads.

The O-ring K 74150 is a precision sealing element designed for the casing of the fuel transfer pump K 74102 in the ZV40/48 engine. Manufactured from high-grade elastomer resistant to fuel, temperature fluctuations, and mechanical stress, it ensures a tight, leak-free interface between pump casing components. By preventing fuel seepage and protecting the interior from contamination, K 74150 safeguards pump efficiency, extends service life, and supports consistent fuel delivery. Its small size belies its importance, as this O-ring plays a vital role in maintaining the integrity and safety of the entire fuel transfer system.

Tihe fresh water preheater, code P51635-14, is an essential thermal-management component in the MAN L21/31 engine, designed to warm the coolant before startup or during low-temperature operation. By raising the temperature of the fresh water circulating through the engine block, the preheater helps reduce cold-start wear, improves combustion efficiency, and enables smoother, faster engine start-up. Particularly valuable in cold climates and marine environments, this preheating system enhances operational readiness and contributes to overall engine longevity.

The lubricating oil pump, code P51501-23, is a vital heart of the MAN L21/31 engine’s lubrication system, responsible for circulating oil under controlled pressure to all critical moving components. By ensuring a continuous supply of clean, pressurized oil to bearings, pistons, camshafts, and gears, the pump minimizes friction, prevents metal-to-metal contact, and supports efficient heat removal. Its robust design and precise flow characteristics make it essential for engine durability, especially in demanding marine environments where uninterrupted reliability is mandatory.

The valve body K 74134 is a critical structural component of the fuel transfer pump in the ZV40/48 engine, designed to house and support the internal flow-control mechanisms. Built to withstand high-pressure fuel delivery and continuous operational stress, this component ensures precise fluid routing, minimal turbulence, and consistent pump efficiency. Its durable construction and corrosion-resistant materials help maintain long-term stability, reduce maintenance requirements, and safeguard the performance of the entire fuel supply system. As the core of the pump’s regulation function, K 74134 plays a central role in ensuring reliable fuel transfer and uninterrupted engine operation.

The tapered connection sleeve K 84469 is a precision-engineered coupling element used to secure the visual flow control device within the Sulzer/Adriadiesel/Jugoturbina/Zgoda ZV40/48 engine’s fluid monitoring system. Its conical design ensures a tight, vibration-resistant seal that maintains optimal visibility and prevents leakage even under fluctuating pressures and temperatures. Manufactured for durability and accurate alignment, this sleeve plays a crucial role in ensuring that operators receive clear, uninterrupted visual feedback on fluid movement, thereby improving diagnostic accuracy and enhancing operational safety.

The lubricating oil cooler, code P51506-22, is a vital heat-exchange component in the MAN L21/31 engine, responsible for maintaining the correct operating temperature of the lubricating oil. By cooling the oil as it circulates through the engine, the cooler prevents overheating, preserves oil viscosity, and ensures stable lubrication across all moving parts. Its robust construction and thermal efficiency are essential for protecting bearings, pistons, and gear systems from thermal stress, making it indispensable for engines operating in demanding marine environments or high-load industrial applications.

The expansion piece K 81136 is a flexible exhaust piping component featuring six corrugations, engineered to absorb thermal expansion, vibration, and movement within the ZV40/48 engine’s exhaust system. Its corrugated design allows controlled flexibility while maintaining strength and gas-tight performance under high-temperature exhaust flow. By reducing stress on rigid piping sections and preventing cracking or premature failure, this expansion piece significantly enhances the durability and reliability of the engine’s exhaust line, ensuring stable operation in demanding marine and industrial environments.

The weld-on piece K 81166 is a durable structural component designed to provide a stable mounting surface for the guide element within the Sulzer/Adriadiesel/Jugoturbina/Zgoda ZV40/48 engine. Manufactured to withstand thermal expansion, vibration, and continuous operational loads, this weldable part ensures precise positioning and secure integration into the engine’s support framework. Its robust design enhances the rigidity of the guide assembly, prevents misalignment over long operating periods, and contributes to the engine’s overall mechanical reliability.

The lubricating oil pump, code P51501-25, serves as the heart of the MAN L21/31 engine’s lubrication system, delivering pressurized oil to all bearings, gears, and moving components. Engineered for durability and flow consistency, the pump ensures that friction is minimized and heat is efficiently dissipated throughout the engine. Its stable performance is essential for preventing component failure, reducing mechanical losses, and supporting long-term reliability, particularly in high-load marine propulsion and industrial power generation applications.

The visual flow control device K 84465 is an eight-position inspection element used in the ZV40/48 engine to allow operators to visually verify fluid movement, direction, and condition within the system. Designed for clarity, durability, and resistance to pressure and temperature fluctuations, this component enhances situational awareness during operation and maintenance. Its multi-position configuration enables precise monitoring of flow changes, making it easier to detect irregularities, contamination, or flow interruptions. By providing immediate visual feedback, K 84465 significantly improves reliability, safety, and diagnostic speed in complex engine environments.

The clamping piece K 81184 is a precision-engineered fastening component used to secure support K 81260 within the heavy-duty structural assemblies of the Sulzer/Adriadiesel/Jugoturbina/Zgoda ZV40/48 engine. Designed to withstand continuous vibration, dynamic loading, and harsh operating conditions, this clamping piece ensures stable positioning of the support frame and prevents loosening or misalignment during engine operation. Its robust construction and exact fit enable reliable long-term anchoring of auxiliary components, contributing to improved structural integrity and dependable overall engine performance.

The fuel oil arrangement, code P51430-28, comprises the integrated system of pipes, filters, valves, and sensors responsible for the preparation, distribution, and management of fuel oil within the MAN L21/31 engine. This carefully configured network ensures proper fuel conditioning—such as temperature control, filtration, and pressure regulation—before injection. By optimizing fuel quality and flow dynamics, the fuel oil arrangement enhances combustion stability, engine responsiveness, and operational safety, especially in variable-load marine environments and power generation facilities.

The threaded pin K 81192 is a precision-machined fastening element used to anchor and secure support K 81260 in the ZV40/48 engine’s mounting systems. Engineered for high tensile strength and resistance to vibration, this threaded pin maintains a stable connection even under demanding operational conditions. Its accurate threading ensures easy installation, secure engagement, and long-lasting structural integrity. Although small, K 81192 plays a critical role in keeping the support assembly firmly in place, contributing to reliable operation and reduced wear of engine components.

The sealing ring K 92030 is a precision–crafted gasket designed to provide a tight, leak-free barrier between the thermometers and their mounting points in the Sulzer/Adriadiesel/Jugoturbina/Zgoda ZV40/48 diesel engine. Built to withstand continuous thermal cycles, pressure variations, and strong engine vibrations, this sealing ring ensures accurate temperature measurement by preventing coolant, oil, or compressed air from escaping around the sensors. By preserving the integrity of the thermometer interfaces and protecting them from wear and corrosion, K 92030 contributes directly to reliable engine monitoring and long-term operational stability.

The turning gear, code P51325-12, is an essential maintenance and safety device in the MAN L21/31 engine, allowing for controlled rotation of the crankshaft when the engine is not running. This feature is critical during inspections, servicing, or startup procedures, ensuring precise positioning of engine components. With its secure mechanical engagement and reliable motorized drive, the turning gear enhances safety, aids in alignment tasks, and supports effective maintenance planning.

The O-ring K 87183 is a precision elastomer sealing component designed for part K 87166, providing essential leak protection and pressure stability in the auxiliary systems of the ZV40/48 engine. Its circular cross-section allows uniform sealing contact, ensuring reliable performance even under high vibration, temperature variations, and continuous operating loads. Made from materials resistant to fuel, oil, and hydraulic fluids, the K 87183 O-ring prevents unwanted leakage and protects sensitive components from contamination or pressure loss. As a small yet critical element, it enhances overall system integrity and contributes significantly to the engine’s long-term reliability and efficiency.

The sealing ring K 92030 is a precision gasket designed to ensure a leak-free and thermally stable interface between the engine thermometers and their mounting points on the Sulzer/Adriadiesel/Jugoturbina/Zgoda ZV40/48 diesel engine. Engineered to resist high temperatures, pressure fluctuations, and continuous vibration, this sealing ring prevents coolant, oil, or compressed air from escaping around temperature-measuring sensors. By maintaining accurate thermal readings and protecting the sensor seating surfaces from wear and corrosion, K 92030 contributes directly to reliable engine monitoring, stable operation, and early detection of abnormal thermal behavior in heavy-duty marine and power-plant applications.

The water washing system on the compressor side, code P51205-03, is a maintenance feature in the MAN L21/31 engine that enables the removal of dirt, salt, and oil build-up from turbocharger components. By injecting a controlled flow of water while the engine is running at partial load, it ensures optimal compressor efficiency, minimizes performance loss, and extends the service life of the turbocharger. This is especially valuable in marine and coastal operations where air contamination is high.