True or False: A shut-off valve is required in gravity feed fuel systems.

A shut-off valve is indeed required in gravity feed fuel systems to ensure safety and control over fuel flow. This requirement is based on the need to prevent fuel leaks and to allow for maintenance or emergencies where the fuel supply needs to be stopped quickly. In a gravity feed system, fuel flows from a tank to the engine or combustion system solely under the influence of gravity, making it vital to have a means to control that flow appropriately. A shut-off valve provides that necessary function, allowing operators to halt fuel delivery when needed, thus reducing the risk of spills or fire hazards.

In contrast, other options do not accurately reflect the requirements for gravity feed fuel systems. While certain systems may not require shut-off valves depending on specific variables such as design or regulatory standards, the general rule for gravity systems maintains the necessity of a shut-off valve for safety and management.