ISO 28523:2009

Overview

ISO 28523:2009 - Ships and marine technology - Guidance for sampling to determine cleanliness and particle contamination - provides practical methods to extract representative fluid samples from lubricating and hydraulic oil systems on ships and marine machinery. The standard explains how to perform dynamic and static sampling, how to collect samples in compliant bottles, and how to prepare samples for particle counting or microscopic cleanliness evaluation to obtain reliable, comparable contamination data.

Key topics and requirements

• Representative sampling
  • Samples must be taken when the system has reached operating temperature and, where possible, from a location with turbulent flow (dynamic sampling) to avoid particle settling.
  • If dynamic sampling is not feasible, static sampling from the system tank is permitted (note: particles > 20 µm settle quickly during static sampling).
• Dynamic sampling rigging
  • Use a sampling device with a flexible capillary; internal diameter should comply with ISO 4021 (minimum 1.25 mm where applicable).
  • Ensure at least 0.5 L of fluid passes through the sampling line before collecting the actual sample. For automatic particle counters, extract at least 0.4 L.
  • Fill sample bottle to 50–80% of its volume, remove the bottle while fluid still flows, and close immediately. Do not immerse the capillary tube into the bottle to avoid contamination.
• Static sampling methods
  • Procedures mirror dynamic sampling steps for filling and handling; vacuum-assisted extraction is an accepted option.
• Sample bottles and labeling
  • Bottles must meet ISO 3722 cleanliness requirements, be sealed when delivered, be chemically compatible and transparent, and carry clear identification (date, plant, sample location, pressure, running hours).
• Automatic particle counting
  • Pre‑checks and preparation include water content measurement (Karl Fischer); automatic counting is allowed only if water < 0.05% mass fraction.
  • Typical preparation: heat to ~65 °C, shake 5 minutes, ultrasonic 15 s, degas under vacuum (50–80 kPa), then perform counting and convert results to ISO-contamination code (ISO 4406).
• Microscopy
  • Used for flushing evaluation and qualitative assessment; follow membrane filtration guidance (e.g., 1.2 µm filters), heat to ~40 °C and shake before filtration, and use a consistent operator for repeatability.

Applications and users

• Target users: ship engineers, marine maintenance teams, oil analysis laboratories, equipment OEMs, classification societies, and technical managers responsible for reliability and contamination control.
• Practical uses:
  • Condition-based maintenance and contamination monitoring of main engines, gears, steering gear, and hydraulic systems.
  • Acceptance testing after newbuilds, repairs, filtration upgrades, or flushing procedures.
  • Providing consistent sample protocols for trend analysis, warranty claims, and contamination-control programs.

Related standards

• ISO 3722 - Fluid sample containers - cleaning/qualification
• ISO 4021 - Extraction of fluid samples from lines of an operating system
• ISO 4406 - Coding of contamination by solid particles
• ISO 11171, ISO 28521 - Referenced for particle counter calibration and guidance on cleanliness grades

Keywords: ISO 28523:2009, sampling, lubricating and hydraulic oil systems, dynamic sampling, static sampling, particle contamination, oil cleanliness, marine maintenance.