What is the primary function of a check valve?

• A. To control the flow of fluid in one direction.
• B. To throttle flow rates.
• C. To connect two pipes of different sizes.
• D. To relieve pressure in a system.

Answer: (A)

The primary function of a check valve is to allow fluid to flow in one direction while preventing backflow. This mechanism is crucial in many piping systems as it ensures that fluids do not reverse direction, which can lead to potential damage or inefficiencies in the system. Check valves are utilized in various applications, such as in water supply systems, waste management, and many industrial processes, to maintain proper flow direction and system integrity.

Other options do not align with the primary purpose of a check valve. Throttling flow rates is typically the role of control valves, while connecting two pipes of different sizes is the function of reducers or adapters. Relieving pressure in a system is the designated role of pressure relief valves, which are designed specifically to manage pressure levels and prevent system failures. Understanding the distinct roles of these valves helps in selecting the right component for the desired application within a piping system.