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.
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 shaft seal K 74149 is a high-performance sealing component designed specifically for the rotating assembly of part K 74123 in the ZV40/48 engine. Engineered to withstand high rotational speeds, thermal changes, and exposure to fuel and lubricants, this seal maintains a reliable barrier that prevents fluid escape and protects internal components from contamination. Its robust elastomeric construction ensures long service life, reduces wear, and supports smooth, efficient operation of the shaft mechanism, making it essential for maintaining the overall integrity of the assembly.