Key principles.
σ = PD/2t
Hoop stress for thin-wall tube. P=pressure, D=diameter, t=thickness.
Limit
Operating stress ≤ yield/safety factor. Yield 30-50% UTS typical.
1.5-4
Aerospace 1.5. Pressure vessel 4. Per code.
Per service
Stainless for chemical. Carbon steel for water. Inconel for aggressive.
B31, BPVC
ASME B31 piping. ASME BPVC pressure vessels. Per code.
1.5× working
Test 1.5× working pressure. Hydrostatic safer than gas.
FAQ
σ = PD/2t for thin walls (D/t > 20). Thick walls use Lamé equations.
Calculate per material yield, safety factor. ASME formulas.
B31 piping. BPVC pressure vessels. Each application has specific code.
Hydro: water-filled, safer. Pneumatic: less leakage detection but faster. Hydro standard for code.
1.5 minimum aerospace. 2-4 industrial. Per code-specified.
Seamless tube/pipe higher integrity. Welded more economical at scale.
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