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 the cover of the centrifugal filter, code P51715-01, includes the components required to service and restore the protective housing of the MAN L21/31 engine’s centrifugal oil filtration system. The centrifugal filter is vital for removing fine contaminants from lubricating oil, ensuring cleaner circulation and reducing wear on internal components. Maintaining the filter cover ensures proper sealing, safe operation at high rotation speeds, and protection of the filtration system from external contaminants. By ensuring the filter performs at peak efficiency, this kit supports longer oil life, improved lubrication quality, and greater overall engine reliability.

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 74152 is a high-performance sealing component specifically designed for the pump impeller K 74123 used in the ZV40/48 fuel transfer system. Exposed to rotational forces, fuel contact, and thermal variations, this O-ring provides essential sealing between the impeller and adjacent housing surfaces. Its durable, fuel-resistant material reduces wear, maintains pressure stability, and prevents internal leakage, ensuring smooth hydraulic performance. The reliability of the K 74152 O-ring directly influences pump output efficiency and helps guarantee uninterrupted and balanced fuel flow throughout engine operation.

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.

The complete exhaust piping K 81100 is a critical subsystem of the Sulzer/Adriadiesel/Jugoturbina/Zgoda ZV40/48 engine, responsible for safely channeling high-temperature exhaust gases away from the cylinders and out of the engine room. Engineered to withstand extreme thermal loads, vibration, and corrosive exhaust compounds, this assembly ensures efficient gas flow with minimal backpressure. Its robust construction supports long-term reliability, while precise alignment and smooth internal surfaces help optimize engine performance and reduce emissions. As a major structural and functional component, K 81100 contributes significantly to the engine’s overall operational stability and environmental compliance.

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 cooler, code P51506-22, plays a crucial role in maintaining the thermal stability of the MAN L21/31 engine by reducing the temperature of circulating lubrication oil. Using an efficient heat-exchange design, it protects the oil from overheating, preserves optimal viscosity, and ensures consistent lubrication performance even under heavy loads. This component helps safeguard bearings and internal surfaces from thermal stress, contributing to longer service life and enhanced performance in marine propulsion and auxiliary power systems.

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.

Kućište ventila K 74134 ključna je strukturna komponenta pumpe za pretakanje goriva na motoru ZV40/48, namijenjena smještaju i stabiliziranju unutarnjih mehanizama za regulaciju protoka. Izrađeno da izdrži visoke tlakove goriva i stalna radna opterećenja, ovo kućište osigurava precizno usmjeravanje fluida, minimalnu turbulenciju i dosljednu učinkovitost pumpe. Njegova robusna konstrukcija i otpornost na koroziju smanjuju potrebe za održavanjem te štite pouzdanost cijelog sustava opskrbe gorivom. Kao središnji element regulacijskog sklopa, K 74134 osigurava stabilan prijenos goriva i neprekidan rad motora.