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Zichai L250-05-022 2nd Piston Ring

Zichai L250-05-022 2nd Piston Ring

Heybeli Marine is a trusted global supplier of class-approved, high-precision marine engine components. The Zichai L250-05-022 2nd Piston Ring (internally categorized under the L250-05 piston group assembly) is a premium-tier secondary ring engineered to original equipment manufacturer specifications. It serves a vital dual purpose as a compression backup and a directional lubricant regulator within the Zichai L250 engine series.

When examining the architecture of a medium-speed engine’s running gear, the placement within the piston ring grooves is highly strategic. As illustrated above, the wiper ring (Napier ring) sits directly below the primary compression ring and just above the oil scrapper ring. This intermediate positioning is crucial for balancing gas containment and oil film distribution along the inner cylinder walls.

Category: Brand: Product ID: 19289

Description

Technical Overview & Dual Functionality

While the 1st piston ring handles the initial thermal shock and peak firing pressure of combustion, the 2nd piston ring operates in a highly dynamic environment where it must seal any escaping blow-by gases while actively scraping away excess lubricating oil.

The L250-05-022 part number specifies an advanced taper-faced or undercut (Napier-type) piston ring profile. During the upward stroke, the ring glides smoothly over the lubricant film; during the downward stroke, its sharp lower edge acts as a mechanical scraper. Fabricated from high-tensile alloy cast iron or cast iron with vermicular graphite, it provides optimized flexibility and an exceptional sealing boundary.

  • Compatible Engine Type: Zichai L250, LB6250, LB8250, 6L250, 8L250, and LC9250 series four-stroke medium-speed marine diesel engines.
  • Part Number / Designation: L250-05-022 (2nd Piston Ring / Wiper Ring).
  • Component Group: Piston Assembly Running Gear Spare.
  • Nominal Cylinder Bore: 250 mm.
  • Material Base: High-grade gray cast iron alloyed with chromium and manganese for enhanced fatigue life.
  • Surface Finish: Precision-ground side faces with an anti-friction phosphated or copperized running layer to aid initial break-in.

Key Features & Performance

  • Tapered Face “Wiping” Efficiency: The outer perimeter features a micro-calculated taper angle. This structural asymmetry lets the ring skim over the oil on the upstroke but scrape oil downward into the crankcase on the downstroke, minimizing oil carry-over into the combustion space.
  • Secondary Compression Backup: It seals the remaining combustion gases that bypass the top ring. By containing this residual pressure, it maintains high brake mean effective pressure (BMEP) and lowers crankcase pressure buildup.
  • Friction Reduction & Scuffing Prevention: The advanced metallurgical structure features excellent natural oil-retention characteristics. This ensures that a stable, microscopic boundary lubrication layer remains intact, protecting the cylinder liner (L250-01-068) from micro-welding or scoring.
  • Perfect Ring-Groove Compliance: Precision axial and radial tolerances prevent structural sticking or carbon jamming within the second groove of the composite piston crown, ensuring steady tangential pressure throughout extended run times.

Why Source from Heybeli Marine?

Worn or low-quality secondary piston rings lose their scraping edge, leading to a massive increase in lubricating oil consumption, severe carbon deposits on the piston crown, fouled exhaust paths, and sudden compression loss. Heybeli Marine secures your technical fleet management with:

  1. Exacting OEM Specifications: Sourced from world-class maritime sealing foundries, our piston rings maintain perfect tangential tension, radial thickness, and free-gap dimensions for hassle-free fitment.
  2. Global Strategic Fleet Inventory: We maintain deep stock allocations of Zichai L250 running gear parts across our international logistics network, allowing fast, 24-hour dispatch to major ports, dry docks, and commercial shipyards globally.
  3. Comprehensive Overhaul Packages: We supply the L250-05-022 ring along with matching 1st compression rings (L250-05-21), oil scraper rings (L250-05-200), combination pistons (250-110), and wet cylinder liners.
  4. Rigorous Testing Standards: Every single production batch undergoes strict elasticity monitoring, light-gap sealing checks, and dimensional verification before being packed for delivery.

Technical Maintenance Note: When overhauling the Zichai L250 ring pack, always verify the directional orientation of the L250-05-022 ring. Tapered or Napier-type wiper rings are directional components; installing them upside down will cause the ring to pump lubricating oil into the combustion chamber rather than scraping it away, resulting in high oil consumption, heavy exhaust smoke, and severe carbon build-up. Always look for the “TOP” or manufacturer’s stamp and ensure it faces upward toward the piston crown. Use a calibrated feeler gauge to confirm the ring end gap and side clearance within the groove before final installation.

Additional information

Brand

Zichai
Model

L250-05-022

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