What type of valve feeds fuel to the drain?

• A. Spring loaded inlet check valve
• B. Ball valve
• C. Globe valve
• D. Stop valve

Answer: (A)

One-way flow control is essential here: fuel must be allowed to move toward the drain, but it must not flow back into the fuel system when pressure changes. A spring-loaded inlet check valve fits this need because it opens to let fuel pass toward the drain when there is forward pressure, and the spring biases the valve shut to block reverse flow when pressure on the drain side drops or reverses. This ensures reliable draining without allowing fuel to backflow into the pump or supply lines.

Ball valves, globe valves, and stop valves are primarily shutoff or throttling devices. They don’t inherently prevent backflow in the drain line and therefore aren’t ideal for feeding fuel to the drain where unidirectional flow is required.