Overfill Prevention & Alarm System

Overfill Alarm System

Early Warning, Maximum Safety During Fuel Deliveries

The Overfill Alarm System is a critical safety function developed to ensure safe fuel tank filling operations and to prevent risks associated with tank overfilling. Integrated into projects by General Petrol, the FIMTEK Overfill Alarm system continuously monitors tank levels with high precision and provides visual and audible warnings before the tank reaches a hazardous fill condition.

This system acts as an early warning mechanism during fuel deliveries, giving operators valuable time to intervene. Its primary purpose is to prevent overfilling before it occurs, thereby protecting personnel, the environment, and critical equipment.

System Architecture and Core Components

The FIMTEK Overfill Alarm system consists of three main components working together as a single safety layer:

• FIMROD Magnetostrictive Level Probe
  Installed inside the tank, it continuously measures fuel (and water) levels with millimetric accuracy in real time.

• FIM7L ATG Console
  Continuously evaluates probe data, manages alarm logic, and triggers alarms at predefined threshold levels.

• External Alarm Unit (Horn / Beacon)
  Installed near the tank filling point, providing a high-volume audible alarm and a highly visible warning light to alert delivery operators.

Together, these components form the first line of defense against tank overfilling during fuel deliveries.

Operating Principle – Early High-Level Alarm

As fuel level rises during delivery, the FIMROD magnetostrictive probe continuously tracks the float position and transmits real-time level data to the FIM7L ATG console. For each tank, a high-level alarm threshold is defined within the console software. This threshold is typically set at approximately 90% of tank capacity, creating a safe operational margin.

When the fuel level reaches this predefined threshold:

1. The FIM7L console immediately detects the condition

2. The configured alarm output is activated

3. The external alarm unit is energized

4. A clear, loud, and unmistakable warning alerts the delivery operator

This allows the fuel transfer to be safely stopped before any overflow occurs.

Technical Alarm Sequence

The technical operation of the Overfill Alarm function follows a structured sequence:

1. Alarm Level Definition
   A high-level alarm point is configured for each tank in the ATG console software (percentage, volume, or level based).

2. Continuous Monitoring
   The FIMROD probe continuously measures the tank level and transmits digital data to the console.

3. Threshold Detection
   When the level reaches the alarm threshold, the condition is detected without delay.

4. Alarm Activation
   The console activates the alarm unit via relay output, triggering the horn and warning beacon.

5. Operator Intervention
   The delivery operator receives the warning and immediately stops fuel flow.

6. Acknowledgement / Reset
   The audible alarm can be acknowledged, while the visual warning remains active until the level returns to a safe range.

Integration with Existing Systems

The FIMTEK Overfill Alarm function can be integrated into existing FIMTEK automation infrastructures with minimal additional hardware and wiring. Thanks to the modular architecture of the FIM7L console:

• Alarm units can be easily connected via relay outputs

• ATEX-compliant barriers and isolation solutions can be applied

• Different alarm thresholds can be configured for different tanks

This approach allows existing stations to significantly upgrade safety levels without requiring a full system replacement.

ATEX-Compliant and Safe Design

The Overfill Alarm system is engineered for safe operation in hazardous environments:

• FIMROD probe: Intrinsically safe (Ex ia), certified for ATEX Zone 0

• FIM7L console: Installed in a safe area; optional Ex-proof enclosure available

• Alarm unit: ATEX-compliant, providing high visibility and high sound output

All system components are designed to ensure no ignition source is introduced in environments where fuel vapors are present.

Benefits for Operators and Facility Owners

Key advantages of the Overfill Alarm system include:

• Prevention of tank overflows and fuel spills

• Reduction of fire and explosion risks

• Protection against environmental contamination and regulatory penalties

• Compliance with safety regulations and industry standards

• Increased operator confidence during fuel deliveries

• Avoidance of costly cleanup operations, product losses, and downtime

Preventing even a single overfill incident can offset the entire investment cost of the system.

Integrated Safety Approach

The FIMTEK Overfill Alarm combines the high-precision measurement capability of the FIMROD probe with the intelligent control algorithms of the FIM7L ATG console. Delivered with General Petrol’s engineering expertise and field integration experience, this solution provides a proactive and reliable safety layer for fuel storage facilities.

In summary, the Overfill Alarm function is an indispensable safety component that prevents overfilling before it occurs, alerts operators at the correct moment, and effectively controls one of the most critical risks in fuel storage and delivery operations.