SECTION 05 / 20
Contamination Science
Contamination science identifies, classifies, and quantifies the sources of particulate, water, and chemical contamination in industrial systems. The three primary contamination categories — built-in, ingress, and generated — require different control strategies and together determine the total contamination load a filtration system must manage.
01 / ENGINEERING PURPOSE
Effective contamination control requires identifying each source contributing to system contamination. Addressing only one source (e.g., ingress via air intake) while ignoring others (e.g., built-in from assembly or generated from component wear) produces an incomplete protection strategy that fails to maintain target cleanliness.
02 / APPLICABLE STANDARDS
03 / KEY CONCEPTS
Built-in contamination
Contamination present in a system before operation begins — machining chips, casting sand, assembly residues, pipe scale, and elastomer particles from installation. New hydraulic systems typically start at ISO 22/20/17 or worse without commissioning flush.
Ingress contamination
Contamination entering an operating system from outside — airborne dust through air intake, water through breather valves, particles through worn rod seals, and external contamination introduced during maintenance.
Generated contamination
Contamination produced internally by system operation — wear particles from bearing surfaces and gear teeth, oxidation products, carbon agglomerates from oil thermal degradation, and corrosion products.
Commissioning flush
Circulation of hydraulic fluid through the new system at full flow before first operation, specifically to remove built-in contamination. Target: ISO 17/15/12 before commissioning. Skipping commissioning flush causes accelerated early-life wear.
Water contamination in fuel
Water in diesel fuel above 200 ppm damages HPCR injector seats through corrosion and micro-pitting. Water enters fuel through condensation in large tanks (atmospheric breathing + temperature cycling), transfer contamination, and seal leaks. Karl Fischer titration (ISO 12937 / ASTM D6304) quantifies water content.
04 / ENGINEERING METRICS
New system typical cleanliness
ISO 22/20/17 (uncontrolled)
Commissioning flush target[ISO 4406]
ISO 17/15/12
HPCR injector water limit[ISO 12937]
<200 ppm
Water in lube oil — coolant leak indicator
>0.1%
Water in lube oil — accelerated oxidation threshold
>0.5%
05 / FAILURE CONSIDERATIONS
06 / RELATED ELIMFILTERS TECHNOLOGIES
07 / RELATED ENGINEERING ARTICLES
ELIMFILTERS Knowledge Center — Contamination Control (contamination-control)
ISO 12937:2000 — Petroleum products — Determination of water by Karl Fischer titration
ASTM D6304 — Standard Test Method for Water in Petroleum Products by Karl Fischer Titration