Water Detection for Marine Fuel and Lube Oil Systems
Protect marine engines and fuel systems with continuous inline water monitoring. Built for offshore and marine environments.
The Challenge
Marine vessels operate in demanding environments where water contamination of fuel and lubrication oil is a constant threat. Water enters through stern tube seals, cooling water leaks, condensation, and poor bunker quality. The consequences of undetected water range from reduced engine efficiency to catastrophic bearing failure.
Fuel System Damage
Water in heavy fuel oil (HFO) causes fuel pump wear, injector damage, and combustion chamber corrosion. Engine shutdowns at sea are dangerous and expensive.
Bearing Failure
Water ingress from stern tube seals or cooling system leaks into lube oil causes catastrophic main bearing failures that can immobilise a vessel.
Bunker Quality Disputes
Water content in bunkered fuel is a common source of disputes. Independent onboard measurement provides evidence of fuel quality at the point of delivery.
Separator Monitoring
Centrifugal separators in the engine room must remove water from fuel and lube oil. Continuous monitoring of separator outlet quality ensures effective operation.
How Zelentech Solves It
Zelentech offers two product lines for marine applications: the ZT-100 Water In Oil Monitor for lubrication oil protection, and the ZT-100 WIFE (Water In Fuel Emulsions) monitor for marine fuel systems.
The Water In Oil Monitor measures total water content in engine lube oil, stern tube oil, and gearbox oil systems — detecting water from seal failures, cooler leaks, and condensation before it reaches levels that cause bearing damage.
The WIFE monitor is designed for water-in-fuel emulsion systems used to reduce NOx emissions. It measures the water-to-fuel ratio in real time, ensuring the emulsion is maintained at the optimal ratio for combustion efficiency and emissions compliance.
Both instruments are compact, loop-powered, and designed for engine room installation where space is limited and conditions are harsh.
Total Water Measurement
Measures dissolved, free, and emulsified water — all forms present in marine fuel and lube oil systems.
Engine Room Ready
Compact, vibration-resistant, and loop-powered. Designed for the space constraints and environmental conditions of marine engine rooms.
Bunker Quality Verification
Independent onboard measurement provides evidence of fuel water content at the point of bunkering.
Trusted Across the Marine Industry
Zelentech water-in-oil monitors are installed aboard vessels across every segment of the marine industry — from container giants and tankers to ferries, yachts, coastguard patrol boats and naval submarines.
Container Shipping
MSC Chicago
Passenger Ferries
Stena Adventurer (Stena Line)
Container / Cargo
Safemarin Chambal (Maersk)
Naval & Coast Guard
Australian Coast Guard
Fishing Fleet
Framtak Hugin
Luxury Yachts
Avangard (Croatia)
Key Specifications
| Applications | HFO, MDO, lube oil, stern tube oil, fuel emulsions |
| Measurement | Total water content (dissolved + free + emulsified) |
| Sensitivity | From 0.01% water content |
| Response Time | 1 second |
| Power | 24 VDC, loop powered |
| Output | 4–20mA + HART |
| Installation | Inline, bypass loop, or separator outlet |
Recommended Products
Need Marine Water Monitoring?
Tell us about your vessel type and monitoring requirements — fuel system, lube oil, or both — and we’ll recommend the right solution.
