Help - Step by step piping design

Hello partners! I'm a new member, and also I'm a beginner at piping design. In fact, I arrived at this wonderful world because my last project at university requires it.

So, here is what I got...

I have to design the piping of my Hydrogen plant. So, as you know, there are plenty of tubes, flanges, valves etc. But what I really need is a guide.

Could anybody tell me the steps to be followed?

I believe this is something like this, but I'm not completly sure:

1-With the volumetric flow and the maximum velocity, calculate area.
2-With area, calculate internal diameter.
3-With tables, seek the ID more similar to the calculated one.
4-Go to ASME B31.3 and use the eq. that is given.
Questions:
S: should it be the value that is given in the tables? or should it be, for example, the 80% of that value to be sure that it will work?
D: should I use the OD? if so, How can I know it before knowing the thickness?

Is that all? Am I missing sthg?

Thanks for your help.

My Friend, what you’re missing is YEARS of experience! I don't mean to be hostile here, but you don't "Learn" on a Hydrogen plant! It's way to dangerous not knowing what you’re doing. And to be honest I'm surprised (kind of anyway) that the powers in control would but someone like you (beginner) it that position! MY $0.02 on the subject.

Thanks a lot friend. Just to clarify the matter. This is not a real project. This is a project for university, and what I have to do is the basics. This is the reason why I'm asking some help. I'm completly aware of the expierence needed to do such a design, but if this forum can't help, then, I do not know what can.

Ooooh! School project … (the light goes on!) *G*!! …Well then I must offer you my apologies, I had misunderstood your post. Being an “old guy” is all too common to see, in this business, unqualified people doing projects, and I had thought this was the utmost in utilization of unqualified staff!
Well then for the reasons I stated in my first post this “project” should be REAL interesting for you! Compressor layout, pipe stress, supporting, hold-downs, spring wedges, & pulsation dampeners …all interesting stuff! Good luck to you on your project. And again my apologies.