🛟

Floating Roof Seal Loss Calculator (Detailed)

AP-42 §7.1.4 / API MPMS 19.2 Rim + Fittings + Withdrawal + Seam

Detailed EFR / IFR / Domed-EFR loss calculation per AP-42 §7.1.4 — decomposes into rim seal, deck-fitting, withdrawal, and (bolted-only) deck-seam losses with seal-type wind exponent and fitting-by-fitting K factors. Replaces the simplified 3–5% reduction factor in the basic Tank Emissions calc.

Tank & Liquid

ft
bbl/yr
psi
°F
psia
lb/lbmol
mph

Seals

bbl/1000 ft²

Deck & Fittings

Equations

Vapor function:

P* = x / (1 + √(1−x))2 ; x = PVA/PA

Rim seal:

LR = (KRa + KRb vn) · P* · D · MV · KC

Withdrawal:

LWD = 0.943 · Q · C · WL / D · (1 + NC·FC/D)

Deck fittings:

LF = Σ Ni · KFi · P* · MV · KC