NFPA 30 Emergency Relief Venting Calculator

NFPA 30 Emergency Relief Venting

Emergency relief venting capacity for aboveground storage tanks exposed to fire (NFPA 30-2015 §22.7.3)

◉ NFPA 30-2015 §22.7.3 STYLE CHECK · NOT A REGULATORY SUBMISSION TOOL

⚠ Indicative tool only, and distinct from the existing Tank Venting (API 2000) calculator. This is NFPA 30's own emergency-venting methodology, structurally different from API 2000's. Table 22.7.3.2 (≤2800 ft²) is entered with interpolation between the standard's own listed points, per its explicit Note 1. For >2800 ft², CFH = 1107×A^0.82 is directly stated as Equation 22.7.3.3 and cross-checked here against Table 22.7.3.3's reference values — four of five checked points matched within 0.1%, one (5000 ft²) showed a larger ~4% gap that wasn't resolved; the formula (the standard's own stated equation) governs this tool's calculation regardless.

Identification

Company

Tank ID

Location

Record Type

Research entries stay private to you for practice/testing. Switch to Official once this is a real design your company should see.

Wetted Area (§22.7.3.2.2)

Tank Shape

D — Diameter ft

Shell Height (vertical) ft

Result

Wetted area A—

Base Emergency Relief Venting Requirement (§22.7.3.2, §22.7.3.3)

Result

Governing method—

Base venting capacity, V—

Liquid-Specific Adjustment (§22.7.3.4) optional

Use liquid-specific properties

L — Latent Heat of Vaporization Btu/lb

M — Molecular Weight

Result

Adjusted capacity: CFH = V × 1337/(L√M)—

Reduction Factors (§22.7.3.5–.7)

Protection Basis (choose one)

Additional 50% reduction applies (§22.7.3.6/.7 miscibility conditions)

Only one protection basis applies per tank. The overall combined factor is never reduced below 0.15, per §22.7.3.6/.7.

Result

Combined reduction factor—

Final required emergency relief venting capacity—

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