Purpose of check valves?

• A. Prevent reverse flow
• B. Allow reverse flow
• C. Increase flow rate
• D. Trap debris

Answer: (A)

The main idea is one-way flow control. A check valve is designed to let fluid move in the intended direction and automatically close if the flow reverses. When forward pressure pushes, the valve opens and the fluid passes through; if pressure tries to push the fluid backward, the valve seats itself and stops the reverse flow. This prevents backflow, which can protect pumps from damage, avoid siphoning between stages, and keep contaminants from crossing into sensitive parts of a system. It’s not about increasing how much fluid flows or trapping debris; those aren’t the primary purposes. The valve’s job is to block reverse flow while allowing normal forward flow.