Within how many feet of the pump suction flange can a control valve be installed in the suction pipe?

The correct answer is based on the requirements set forth in fire protection standards, which typically dictate the installation practices for control valves in relation to the pump suction flange. Installing a control valve within 50 feet of the pump suction flange allows for adequate fluid dynamics, ensuring that the flow of water can be maintained properly without causing undue pressure drops or cavitation issues in the pump.

This distance is critical because closer installations may interfere with the pump's ability to maintain adequate suction pressure, potentially leading to operational problems during emergency situations. Furthermore, adhering to the guidance of a 50-foot distance not only conforms to regulatory standards but also enhances overall system reliability and performance during use.

In summary, the specification of 50 feet ensures that the system operates effectively and safely, emphasizing the importance of proper valve placement within fire protection systems.