◉ API 650 §5.10 STYLE CHECK · NOT A REGULATORY SUBMISSION TOOL
⚠ Indicative tool only. Formulas checked directly against the standard's page images. T, U, and p (the design pressures from Appendix R load combinations with balanced/unbalanced snow load) are not computed by this tool — enter your project's governing values directly. This tool doesn't cover frangible-roof detailing (§5.10.2.6) or the full roof-to-shell joint compression-ring design (Appendix F) beyond the single participating-area check in §5.10.5.2.
Identification
Research entries stay private to you for practice/testing. Switch to Official once this is a real design your company should see.
Roof Type & Units
Supported Cone Roof — Rafter Spacing (§5.10.4.4)
Minimum roof slope is 1:16 unless the Purchaser specifies otherwise (§5.10.4.1).
p = uniform pressure from the governing Appendix R load combination.
Result
Maximum allowable rafter spacing b—
Governing limit—
Self-Supporting Cone Roof — Thickness (§5.10.5.1)
Result
From T (balanced snow)—
From U (unbalanced snow)—
Minimum by standard (5mm / &frac316;in)—
Required nominal thickness (governing)—
Corroded thickness cap check (≤13mm / ½in)—
Roof-to-Shell Joint Participating Area (§5.10.5.2)
⚠ Unlike the formulas above, the standard doesn't give this one an SI/US-split with explicit units — every other formula in this tool states its variables' units directly (mm/in, MPa/psi, kPa/psf); this one doesn't, and no clearer version turned up elsewhere in the standard. Enter p and Fa in the same pressure unit (e.g. both MPa, or both ksi) so the ratio is self-consistent, and treat the result with appropriate caution rather than as verified to the same standard as the rest of this tool.
Result
Required participating thickness at joint (same length unit as D)—
Self-Supporting Dome / Umbrella Roof — Thickness (§5.10.6.1)