- Add up the total number of drainage fixture units (dfu) for each sanitary branch.
- Determine the sanitary branch sizes using the dfu values.
- Calculate the size of the main building drain using the total of all dfu values.
- Size the vents using an IPC table and the dfu values.
Hereof, how do you measure the size of a pipe?
Measure the Outside Diameter (OD) of your pipe or pipe fitting:
- Wrap a string around the pipe.
- Mark the point where the string touches together.
- Use a ruler or measuring tape to find the length between the tip of the string and the mark you made (circumference)
- Divide the circumference by 3.14159.
Subsequently, question is, is pipe measured ID or OD? In short: Tube is measured by outside diameter, pipe is measured by inside diameter. There is often confusion as to which size die the customer actually needs - Pipe Size or Tubing Size. Keep in mind that pipe size refers to a nominal - not actual - inside pipe diameter. Schedule refers to the pipe's wall thickness.
Similarly, how are sanitary fittings measured?
All sanitary piping is measured in tube OD. If you are holding a sanitary fitting in your hand, measure the outside diameter of the tube section of the fitting. That is the correct size, not what the face of the end fittings measures. You can buy fittings and tubing in sizes ranging from ½ through 12”.
How do you measure a pipe flange?
For a regular pipe flange, first measure the flange's outside diameter (O.D.). This can be accomplished by measuring from the outside edge of the flange to the opposite outer edge. Next, measure the inside diameter of your flange. Thickness should also be factored in when measuring flanges.
