3. Math Review

Question 1

What are the standard pipe sizes? What can commercial pipes go up to?

Answer 1

1/8, 1/4, 3/8, 1/2, 5/8, 3/4, 1, 1 1/4, 1 1/2, 2. Up to 1 foot.

Question 2

What objects do plumber draw all of their measurements off of in new construction?

Answer 2

Everything is measured off of a fire hydrant and or manhole lid

Question 3

What is all US plumbing measurements in?

Answer 3

English Standard

Question 4

What are the most common offset fittings for water and for drains?

Answer 4

Water is 90, 45. Drain is 22 1/2

Question 5

How do you calculate Fall, Run, Grade

Answer 5

F over R by G. Circle calculations like electrical

Question 6

How much does a drain need to fall per 1 foot?

Answer 6

1/4 inch every foot

Question 7

Why are drain grades measured at such a precise grade?

Answer 7

So the water does not run past the solids leaving it in the pipe

Question 8

How much does water weigh?

Answer 8

62.5 lbs per cubic foot

Question 9

What is Head Pressure?

Answer 9

Amount of water pressure in a column between two points at different heights. Stacking water. Pipe of 1 foot of water has 1 foot of head, etc.

Question 10

What is the amount of psi in a 1 foot vertical pipe at its base?

Answer 10

0.434 psi

Question 11

What is the formula for psi?

Answer 11

Pressure = head x constant (0.434)