Which type of fill device must be installed outside of the vehicle to prevent gas leakage?

The correct answer is the remote fill device. This type of fill device is specifically designed to be installed outside of the vehicle, allowing for safe and efficient dispensing of LP-gas without the need for direct access to the vehicle's interior. The installation of a remote fill device helps minimize the risk of gas leakage into the confined space of the vehicle, which can be hazardous.

By positioning the fill device externally, it ensures that any potential escape of gas can dissipate into the open air rather than accumulating in an enclosed environment, where it could pose risks of explosions, fire, or inhalation hazards. The remote fill device also allows operators to fill the vehicle from a safer distance, further enhancing safety protocols during the refueling process.

Other types of fill devices are designed for different operational setups that may not prioritize the same safety measures regarding gas leakage containment and external access.