Submarine: Fuel Water Detection Solution
Reliable Fuel–Sea Water Interface Monitoring System Using SBEM FUWS-10 Sensors
Challenge: Accurate Flow Monitoring in Submarine Systems
In submarine environments, maintaining the correct boundary between fuel and sea water is crucial for operational safety and efficiency.
Continuous fuel transfer and ballast operations create complex interfaces between nonconductive fuel and conductive sea water.
Detecting this interface accurately under high pressure, varying temperatures, and confined installation conditions is a major challenge for the onboard control system.
SBEM’s Engineering Solution
SBEM developed the Fuel Water Sensor (FUWS-10 Series), a precision-engineered system consisting of two integrated components:
Primary Converter (Model: FUWS-10-PC)
Detects capacitance changes corresponding to the interface level between fuel and sea water.
Secondary Converter (Model: FUWS-10-SC)
Converts these capacitance variations into relay signals for control system actions while also powering the primary converter.
This advanced system ensures accurate boundary detection, supports real-time relay actuation, and maintains reliable communication with submarine service control systems.
Working Principle
- The Primary Converter (FUWS-10-PC) operates on the principle of capacitance change.
- It functions as a cylindrical capacitor, where the internal electrode is insulated with fluoroplastic and the external shell acts as the screen.
- When the space between the electrodes is filled with fuel (air or oil), the capacitance remains minimal.
- When sea water fills the space, the capacitance increases significantly.
- This variation is detected and sent to the Secondary Converter (FUWS-10-SC).
- The secondary unit converts the capacitance signal into a relay output, which changes state when the electrode senses water or fuel.
- The relay output is then transmitted to the submarine’s control system for indication or automated operation.
Why SBEM’s Solution Stands Out
Defence-Grade Design:
Engineered specifically for submarine applications under highpressure marine environments.
High Accuracy:
Maintains ±10 mm alarm accuracy even under long-term immersion.
Pressure Resilience:
Operates efficiently at up to 40 kg/cm² medium pressure.
Complete Isolation:
Ensures electrical safety between fuel, sea water, and instrument circuitry.
Compact & Durable Build:
Constructed using SS316 and aluminium alloy for corrosion resistance and long service life.
Fast Response:
Detects interface level changes instantly, enhancing control reliability.
Integrated Power Supply & Relay:
Secondary converter also acts as a power and relay unit for simplified system integration.
Fully Sealed Construction:
IP67-rated protection ensures durability in humid and submerged environments.
Applications
Fuel-Sea Water Interface Detection in submarine fuel systems
Fuel Transfer System Monitoring for tank-to-tank operations
Boundary Detection in Ballast Tanks during pressure equalization
Oil-Water Separation Systems in marine and defence-grade installations
Control Feedback to SECS (Service Equipment Control System) in submarines
Monitoring Distillate and LSHS Diesel Systems
Leak or Intrusion Detection in fuel storage tanks
Underwater Vessel Automation Systems for safe fluid level management
Outcome: Reliable Defence-Grade Performance
SBEM’s FUWS-10 Fuel Water Sensor Solution provides precise and consistent detection of the fuel–sea water boundary under extreme submarine operating conditions.
With robust build quality, intelligent conversion electronics, and reliable relay-based communication, the system ensures error-f ree operation, safety assurance, and dependable performance across critical defence marine applications.