How long would it take to completely flush a 4-inch water main that is 5,000 feet long at a flow rate of 325 gallons per minute?

To determine how long it would take to completely flush a 4-inch water main that is 5,000 feet long at a flow rate of 325 gallons per minute, you first need to calculate the total volume of water in the pipe.

To find the volume of a cylindrical pipe, the formula is:

Volume = π × (radius²) × height

Where:

• The radius for a 4-inch diameter is 2 inches (or 0.167 feet).

• The height is the length of the pipe, which is 5,000 feet.

Converting the radius into feet:

2 inches = 2/12 feet = 0.167 feet

Now calculating the volume:

Volume = π × (0.167²) × 5000

= 3.14 × 0.02789 × 5000

≈ 439.822 gallons

Next, to find out how long it would take to flush that volume at 325 gallons per minute, you divide the total volume by the flow rate:

Time = Total Volume / Flow Rate

= 439.822 gallons / 325 gallons per minute

≈ 1.352 minutes

However, this estimate seems to have discrepancies when calculating for flushing