How times have changed in 30 years regarding “materials of construction” in hazardous materials processes. I grew up in process safety, seeing nothing but metallic piping systems; today, I bet I see piping systems made from non-metallic products upwards of 25% of the time. This is becoming increasingly acceptable in one specific process I do a lot of work with, so I can not provide specifics as it could create a trail back to some of my clients. Just know that many of the processes are PSM/RMP-covered processes.
ASME B31.3 addresses non-metallic piping systems in Chapter VII, Nonmetallic Piping and Piping Lined With Nonmetals.
In this article, I want to discuss Part 10, Inspection, Examination, and Testing of Nonmetallic Piping Systems Used in a PSM/RMP-covered process. For those who are not SAFTENG members, just know that ASME B31.3 requires many of the same examination and testing requirements for nonmetallic piping systems as it does for metallic piping systems. Two (2) very CRTICIAL PROHIBITIONS for non-metallic piping are the SAME as metallic piping:
- PVC and CPVC piping shall NOT be pneumatically tested!
-
Initial Service Leak Test applies in its entirety for Category D Fluid Service ONLY!
Here are the other examination and testing requirements for NON-metallic piping systems: