Check valves are used in hydraulic systems to which purpose?

• A. Block flow
• B. Increase flow
• C. Mix fluids
• D. Cool the system

Answer: (A)

Check valves enforce one-way flow in hydraulic circuits. They open to let fluid move forward but seal when pressure tries to push fluid backward, preventing backflow. This helps keep actuators in the desired position when the pump isn’t actively delivering flow and protects components from reverse flow that could cause damage or loss of pressure in other parts of the system. They’re not designed to increase flow, mix fluids, or cool the system—that would require other components like pumps, mixers, or heat exchangers.