: : #3: Not sure you have enough info; you may need head, pressure, specific gravity of the fluid.

: Show him the math for the flow calc. How is to learn without knowing the formula. He will not have access to Google when he tests for his journyman's card.

I am Sorry YOUR correct Here is The Formula I use

.4058 x GPM divided by d Sq.

For example lets try it this way

3" pipe 180 GPM

.4085 x 180 = 73.53

DIA Sq = 9 into 73.53 = 8.17 FPS

WANT to prove it?

Lets do the following

d x d x v x 5/2

3 x 3 = 9 9 x 8.17 = 73.53 5/2 73.53 divided by 2 = 37.76 TIMES 5 = 183.8 CLOSE enough for field guessing.