Indian Standard tank shell minimum thickness and unstiffened shell height (IS 803-1976, §5.1, §6.2–6.3)
◉ IS 803-1976 (REAFFIRMED 2006) STYLE CHECK · NOT A REGULATORY SUBMISSION TOOL
⚠ Indicative tool only, and a distinct standard from the existing API 650-based Shell Design and Wind Girder calculators. IS 803 is India's own domestic tank design code — structurally similar to API 650 but with its own formulas, joint efficiency scheme, and thickness tables, verified directly against this edition's page images. This tool doesn't cover Appendix B (alternate shell design) or Appendix C (vent sizing) — good candidates for a follow-up pass. Confirm this is your current edition/amendment before relying on it for a real design; this is the 1976 standard, Edition 2.1 (1984), reaffirmed 2006.
Identification
Research entries stay private to you for practice/testing. Switch to Official once this is a real design your company should see.
Allowable Stress (§5.1.1)
Result
Allowable stress S—
Shell Course Minimum Thickness (§6.3.1–6.3.3.2)
Joint efficiency E = 0.85 if radiographed per this code, 0.70 if not (§6.3.2). Formula: t = 4.9(H−0.3)DG/(SE) [N/mm²] or 50(H−0.3)DG/(SE) [kgf/cm²].
Result
Joint efficiency E used—
Calculated thickness (§6.3.3.1)—
Minimum nominal thickness by diameter (§6.3.3.2)—
Governing minimum thickness (greater of the two)—
Add any required corrosion allowance to this result (§6.3.3.3). Maximum nominal shell thickness is 40mm, or 75mm for insert plates of IS:2002 Grade 2B / IS:2041 steel (§6.3.3.4). Minimum internal vacuum to design for, if unspecified by the purchaser, is 500 N/m² (50 kgf/m²) (§6.3.1.3).