What is the maximum working pressure for carbon steel pipe nipples?

FOR REFERENCE ONLY ! This information is a reference guide only. Specifying the correct pipe schedule and pressure class of fitting depends on many factors. It is the ultimate responsibility of the end user's piping engineer to specify the correct pipe schedule and pressure class of fitting which will meet the maximum operating pressures / temperatures of the system for safe operation in the intended application.

NOTE:

Pressure rating charts should be used as a guide only. For pressure over the stated maximum or temperatures over 100 ° (37.7 °C), independent testing by the end user is recommended. It is solely the end user’s responsibility to determine the suitability of the pipe nipple for the intended service.

Additional Resources:

https://support.boshart.com/what-is-the-difference-between-cw-and-erw-welded-pipe