Excuse me "Sabir" but, if you're a "Piping Engineer" - how is it that you cannot have access to all of the necessary technical reference material normally available to professionals such as yourself?
I ask this because if you have access to the internet then, you should'nt have any problem searching online for your most of the answers to your questions especially some of the ones that you may not find in the normally accessible technical reference publications that are used on a daily basis by piping engineers...
I await your clarification. :)
Respectfully,
Henry
The some of the answers you are looking for are contained in the API specification for Line Piping; API Specification 5L.
As for what is: CS, SS, duplex, etc., you can look in any basic metallurgy textbook or materials science text book for most of those answers. In general; cs - carbon steel, ss - stainless steel (ferritic, martensitic, austenitic, duplex, and precipitation hardened), duplex - stainless steel composed of ferritic and austenitic microstructures, austenite - when speaking of carbon steel - iron at high temperature where all the carbon is in solution with the iron, it is soft, ductile, and nonmagnetic at the high temperature.
Carbon content is dependent on the material, i.e., carbon steel meeting ASTM 36 versus ASTM A572 grade XX, or austenitic stainless steel per ASTM A240 type 304 alloy versus type 32 alloy. ASTM specifications could be used or you can search the internet for information available from suppliers or manufacturers.
As a newly minted engineer, you should begin to amass a good reference library. This is where you'll kick yourself in the butt for selling your text book back to the university bookstore for $0.30 on the dollar.
Good luck - Al