Reduced to the basics, you should use the thin wall pressure vessel equation:
t = (P [·] r)/[σ]
where
t = pipe wall thickness
P = pressure
r = pipe outer radius
[σ] = pipe material strength (yield or equivalent)
There are other factors, such as corrosion loss factor, fracture due to defects, thick wall pipe considerations, etc. You will need to do a complete engineering analysis to account for all factors.
Regards,
Cory
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