What is the relationship between pipe diameter and pressure within an irrigation system?

• A. Larger diameter equals higher pressure
• B. Smaller diameter equals higher pressure
• C. Larger diameter equals lower pressure
• D. Pressure is not affected by pipe diameter

Answer: (C)

In an irrigation system, the relationship between pipe diameter and pressure can be understood through the principles of fluid dynamics. When water flows through a pipe, the diameter of that pipe directly influences the pressure of the water within it due to resistance and friction.

A larger diameter pipe allows for a greater volume of water to flow through with less friction. As a result, the pressure drop (loss of pressure) across the length of the pipe is minimized. Conversely, when the diameter of the pipe is smaller, the same volume of water must pass through a narrower space, which increases the resistance and friction. This increased friction leads to a higher pressure drop, meaning that the pressure at the end of a smaller diameter pipe would be lower than that in a larger diameter pipe for the same flow rate.

Hence, the statement that a larger diameter equals lower pressure is accurate in the context of how water flows in irrigation systems, as it indicates that larger pipes can sustain lower pressure losses, maintaining more consistent pressure throughout the system.

This understanding helps in proper design and implementation of irrigation systems, ensuring optimal efficiency while managing water resources effectively.