In the given example, the 60 gallons per minute flow is associated with which pipe diameter?

In the given example, the 60 gallons per minute flow is associated with which pipe diameter?

• A. 1/2 inch
• B. 1-1/2 inch
• C. 2 inch
• D. 3 inch

Answer: (B)

The flow rate in a pipe is determined by how fast the water can move (velocity) and how much cross-sectional area the pipe provides. In sizing for a given flow, you use Q = V × A and pick a practical velocity range for water in pipes (roughly in the ballpark of 5–8 ft/s for small to medium pipes). With 60 gallons per minute, choosing a one-and-a-half inch pipe gives a cross-sectional area of about 2.8 square inches. That puts the velocity at around 6–7 ft/s, which is a reasonable, typical value for this flow. If you used a much smaller pipe, like one-half inch, the area is only about 0.2 square inches, which would force the water to move extremely fast (nearly 100 ft/s). That’s far beyond practical or acceptable piping conditions due to high friction losses and noise. Using a much larger pipe, such as a two-inch or larger diameter, would lower the velocity and still carry the flow, but the problem’s standard chart pairs 60 gpm with the one-and-a-half inch size, reflecting common design practice and typical velocity targets. So, given the common sizing approach and the example’s pairing, 60 gpm aligns with a one-and-a-half inch pipe.

The flow rate in a pipe is determined by how fast the water can move (velocity) and how much cross-sectional area the pipe provides. In sizing for a given flow, you use Q = V × A and pick a practical velocity range for water in pipes (roughly in the ballpark of 5–8 ft/s for small to medium pipes). With 60 gallons per minute, choosing a one-and-a-half inch pipe gives a cross-sectional area of about 2.8 square inches. That puts the velocity at around 6–7 ft/s, which is a reasonable, typical value for this flow.

If you used a much smaller pipe, like one-half inch, the area is only about 0.2 square inches, which would force the water to move extremely fast (nearly 100 ft/s). That’s far beyond practical or acceptable piping conditions due to high friction losses and noise. Using a much larger pipe, such as a two-inch or larger diameter, would lower the velocity and still carry the flow, but the problem’s standard chart pairs 60 gpm with the one-and-a-half inch size, reflecting common design practice and typical velocity targets.

So, given the common sizing approach and the example’s pairing, 60 gpm aligns with a one-and-a-half inch pipe.