How To Calculate Orifice Size

When creating a piping system, it's important to know how large your restrictive device, or orifice, should be because it determines the appropriate pressure level and flow rate of the system. There are a few reasons why you might want to install an orifice, which include increasing the line pressure and decreasing the flow through the line. You can calculate the orifice size using a formula, but you will need to know a few key numbers before you begin.

Step 1

Write down the flow of the liquid that will be going through the piping system in cubic feet per second. For example, the flow of the liquid in a system might be 8 cubic feet per second.

Step 2

Write down the velocity of the liquid flowing through the piping system in feet per second. The velocity of the liquid in the system described in Step 1 might be 2 feet per second, for example.

Step 3

Divide the flow of the liquid by the velocity of the liquid to determine the area of the orifice in square feet. In the above example, you would divide 8 by 2. The total area of the orifice would be 4 square feet.