easy-eFor which purpose???
You seem to be asking a very broad question. That is why I stated before that your process engineer should be able to tell you which base material you should use for a specific application.
But maybe the following will help.
The selection of the material to be used for each system is based on an evaluation on the following factors:
1. Requirements and limitations of the building and piping codes
2. The fluid in the pipe
3. The pressure and temperature of the fluid in the pipe
4. The location and external environment of the pipe
5. Availability of the material
6. The expected life of the facility where the system is to be installed
7. The installed cost of the system
The first four factors relate to safety and are of primary importance. The last three are related to the economics of the project and are weighed to suit.
The above was an excerpt from “PIPING HANDBOOK†sixth edition (great resource by the way)
So if you know the pipe codes & standards as you stated, you then should be able to apply that knowledge to the above factors and determine your base material. Or am I missing your point completely?