# Plumbing Isometrics Tutorial

In this Plumbing Tutorial, we will explore the importance of Plumbing Definitions. Table 709.1 and Table 709.1 footnotes will also be covered.

# Pythagorean Theorem

For any right triangle, the square of the hypotenuse is equal to the sum of the squares of the other sides.

Run for the door! Cover your ears – there is that “C” word.

Does this bring back school day memories?

## Forget about Pythagorean Theorem, it’s just simple math.

Calculating C, travel, or hypotenuse is basic math for anybody involved in the building trades.

I have used this formula for sheet metal fabrication. Welders need it as well as Plumbers, Mechanical, and GC Contractors.

### Struggling with Plumbing Isometric, Vents and Drains?

Check out NCCTI’s Plumbing Tutorial –

# Plumbing Contractor Exam Math 101

Can you tell me why people flunk the Plumbing Contractor Exam by one or two questions?

Plumbing Offset Language

Here is a Plumbing Exam Question that pops up from time to time. Answering such questions correctly just might push you over the top.

## A sewer is being installed with a 1/8 inch fall for a distance of 100 feet. How much lower will the discharge end over the inlet end?

Here comes that C word!

Let’s covert 1/8 inch to a decimal equivalent  –   1 ÷ 8 = 0.125

0.125 x 100 = 12.5 feet lower or for every 8 – 1/8s  the pipe drops a foot so 100 divided by 8 = 12.5 feet

### Pretty simple, How about – if the set = 12.5 and the run = 100, what would the travel equal?

Let’s word this question differently. A sewer installed with a 1/8 inch per foot slope and falls 12.5 feet. How long is the sewer pipe?

C – Travel – Hypotenuse

# Answer to Free Plumbing Exam Question

The column of water is 50 foot high.

50’ x .434 = 21.7 psi

## On the Plumbing exam, this question might get turned around.

For example;

What is the height of a container that 65 psi is measured at the bottom of the container?

### Need more help to prepare for the North Carolina Plumbing Contractor Exam?

No problem, just sign up for a Plumbing Contractor Practice Exam or order NCCTI’s Plumbing Tutorial.

http://www.nccti.com

# Free Plumbing Contractor Exam Question

First, let’s define head – amount of water pressure in a column between points at different elevations that is expressed in feet.

Why do we care about pressure head? Because it’s on the exam, savvy?

## Understanding Water Pressure

Let’s take a look at the following example:

Cubic feet conversion to psi

### Now I will break it down further

0.434 psi = 1 foot and 2.31 feet = 1.0 psi