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FLOW DIAGRAMCURRENT · v1.0.0DIAG-WATER-CONT-PATHS

Water Contamination Ingress Pathways — Diesel Fuel Systems

Identifies and maps the five primary water ingress mechanisms in diesel fuel and hydraulic reservoirs to enable targeted prevention design. Water contamination is the primary failure driver in HPCR fuel injection systems and the principal cause of microbial growth in diesel fuel tanks. Each ingress pathway requires a specific prevention measure.

Water Contamination Pathways in Fuel and Hydraulic SystemsDiagram showing five water ingress pathways into a central fuel/hydraulic tank: atmospheric condensation through breather vent, contaminated fill via fill cap, worn shaft seals, cross-contamination from connected circuits, and airborne humidity ingression. Right side shows consequence chain: free water accumulation leading to microbial growth, filter plugging, injector corrosion, and HPCR pump damage. Detection box shows Karl Fischer titration per ASTM D6304 and ISO 12937 with target below 200 ppm wt water content.WATER CONTAMINATION INGRESS PATHWAYSFuel & Hydraulic Systems — ASTM D6304 · ISO 12937 · ISO 16332FUEL /HYDRAULICTANKFREE WATER (bottom layer)BREATHER VENTatmospheric humiditycondensation cycleFILL CAP /FILLINGwet fuel /dirty nozzleWORN SEALS /GASKETSshaft ingressCROSS-CONT.CIRCUITreturn line waterAIRBORNEHUMIDITYhygroscopicabsorptionconsequenceMICROBIAL GROWTHHIF bacteria, fungal colonies(free water >200 ppm wt)FILTER PLUGGINGbiomass + wax depositsΔP spike → bypass openINJECTOR CORROSIONnozzle erosion, stictionspray pattern degradationHPCR PUMP DAMAGEplunger/barrel seizure2000 bar clearance failureFREE WATERaccumulated at tank bottom>200 ppm wt saturationDETECTION — ASTM D6304 / ISO 12937Karl Fischer Coulometric TitrationTarget: <200 ppm wt (dissolved) · Action: >500 ppm wt (free water present)ISO 12937 §6 — detection limit 10 ppm wt · ASTM D6304 — diesel/hydraulic fluidISO 16332 — water separator efficiency test >95% water removal at rated flowPREVENTION TECHNOLOGIESHYDROCORE — coalescing water separator, bulk free-water removalSYNTEPORE — glass-fiber fuel media, hydrophobic coating repels waterTURBOCORE — 3-stage fuel treatment: pre-filter + coalesce + finalDesiccant breather recommended on all non-pressurised vent portsASTM D6304 · ISO 12937 · ISO 16332
Central element: a fuel or hydraulic reservoir tank shape. Five ingress pathways shown as arrows pointing into the tank. Top-left: condensation from temperature cycling with water droplet symbols. Top-right: fill cap splash or rain ingress. Left: breather vent admitting humid air shown as a dashed arrow. Bottom-left: worn shaft seals allowing external water ingress. Bottom-right: transfer cross-contamination from contaminated fluid during transfers. Right side of diagram: consequence chain — arrow leaving tank labelled free water present, then four stacked consequence boxes: microbial growth from sulphate-reducing bacteria, filter plugging at the hydrocarbon-water interface, injector corrosion, and HPCR pump damage. Detection box below: Karl Fischer titration per ASTM D6304 and ISO 12937, target below 200 ppm by weight.

GOVERNING STANDARDS

ASTM D6304
ISO 12937
ISO 16332

ELIMFILTERS TECHNOLOGIES

HYDROCORE™
SYNTEPORE™
TURBOCORE™

APPLICABLE SYSTEMS

Fuel Cleanliness
Hydraulic Protection

REVISION METADATA

Versionv1.0.0
Statuscurrent
Last Reviewed2026-07-08
Next Review2027-07-08

RELATED ENGINEERING ARTICLES

→Water Contamination Fuel
→Diesel Fuel Filtration
→Hpcr Fuel System Cleanliness
→Contamination Control

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