If outside, piping shall be under the vehicle and _______________.

When considering the installation of propane piping outside a vehicle, it is crucial for safety and efficiency that the piping is positioned correctly in relation to insulation or false bottoms. The correct answer indicates that piping should be placed below any insulation or false bottom.

This positioning is imperative because it helps to protect the piping from exposure to the elements, preventing potential damage that could lead to leaks or hazards. Insulation or false bottoms are typically used for thermal protection, and having the piping located beneath them ensures that the system remains insulated from external temperature fluctuations. This can also prevent interference with the vehicle's operation and maintain the integrity of the propane delivery system.

Piping situated above insulation runs the risk of being exposed to environmental factors, such as moisture or excessive heat, which can compromise the integrity of the piping and thus the safety of the propane system. Similarly, routing pipes alongside the vehicle or within the vehicle interior poses additional safety concerns, as they could be subjected to physical damage, leaks, or even create fire hazards if not adequately protected.

Therefore, placing the propane piping below any insulation or false bottom strikes the right balance of safety, functionality, and compliance with best practices for propane systems in vehicular setups.