Alert no. 109 | 28 February 2023 | Version

Rubber seal missing from gravity feed fuel cap on explosives charge up vehicle

What happened?

A mobile processing unit fitted with a dual fuel fill system was fitted with a faulty fuel cap. The fuel cap was missing the rubber seal, which created a potential fire hazard.

How did it happen?

An oversight has failed to identify the fuel cap for the gravity feed refuelling system was missing a rubber seal. The seal is critical to maintaining fuel tank pressurisation during the fast fuel process.

Key issues

• When the rubber seal is missing from the gravity feed fuel cap, increased pressure from the fast fuel process may cause fuel to spill from the gravity feed fuel cap.
• A previous incident resulted in a spill of diesel fuel from a defective gravity feed fuel cap onto hot engine parts, causing a fire and full loss of the charge up vehicle.

Recommendations

Operators of plant and equipment fitted with fast fuel systems should:

• review hazard and risk registers to determine if hazards associated with fast fuel systems have been identified and controls put in place
• conduct inspections on all vehicles fitted with fast fuel receivers to ensure that the gravity feed fuel cap is fitted with the correct seal
• ensure that an effective preventative maintenance system includes regular inspections on vehicles fitted with fast fuel receivers to ensure that the gravity feed cap is fitted with the correct seal
• ensure that workers who operate, refuel and maintain equipment fitted with fast fuel receivers have appropriate training in their function, operation, use and inspection, including the role of the seal on the fuel cap
• ensure AFFF fire suppression systems for mobile equipment have been designed and engineered in accordance with relevant standards, such as AS 5062:2022 – Fire prevention and protection for mobile and transportable equipment.