Technical FAQs

What is CIOD and IPS?

CIOD stands for Cast Iron Outside Diameter and is the diameter standard used for AWWA C900 PVC pipe (e.g., blue potable water pipe). 

IPS is Iron Pipe Size, also known as DIPS or Ductile Iron Pipe Size, and is the diameter standard used for ASTM D2241 PVC pipe. (Note, other diameter standards do exist, such as, PSM – Sewer, PIP – Irrigation, Schedule 40/80/120 – Plumbing & Water Well)

Also, consider the following:

  • Aside from compatibility with existing connections, there is no distinct advantage of using one pipe diameter standard over the other.
  • No two are directly interchangeable.