1. ## Water pipe...

Came across this annoying problem:

Determine amt. (gal.) of water per hr. delivered through a 6" pipe, inside diameter 6.065".
Water travels at 10' per sec. 1 gallon = 231 cu. in.

Anybody understand it?

I ended up with ~54,000 gal. per hr.

2. ## Re: Water pipe...

Here are my calculations:

The cross-sectional area of water is:

$$\pi\cdot \left( \dfrac{6.065}{2}\right)^2 \text{ in}^2$$

Area times positional velocity gives volume per time:

$$\pi\cdot \left(\dfrac{6.065}{2}\right)^2\text{ in}^2\cdot \left(10\text{ ft/sec}\right)\cdot \left(12\text{ in/ft}\right) \cdot \left( 3600\text{ sec/hr}\right) \cdot \left( 1/231\text{ gal/in}^3 \right) \approx 54,000 \text{ gal/hr}$$

I get the same answer as you.

3. ## Re: Water pipe...

Phewww.....thanks Slip!!!

4. ## Re: Water pipe...

Originally Posted by DenisB
Came across this annoying problem:

Determine amt. (gal.) of water per hr. delivered through a 6" pipe, inside diameter 6.065".
Water travels at 10' per sec. 1 gallon = 231 cu. in.

Anybody understand it?

I ended up with ~54,000 gal. per hr.
How can a 6" pipe have an inside diameter larger than 6"?

5. ## Re: Water pipe...

Originally Posted by Debsta
How can a 6" pipe have an inside diameter larger than 6"?
The pipe is called a 6" pipe. But, in reality, it is slightly larger than 6" in diameter. This is common where companies will round measurements to the nearest unit rather than display an actual measurement. $6\approx 6.065$.