Fixed foam discharge outlet count, application rate, and discharge time for tank fire protection (NFPA 11-2021 §5.2, §5.3)
◉ NFPA 11-2021 CHAPTER 5 STYLE CHECK · NOT A REGULATORY SUBMISSION TOOL
⚠ Indicative tool only. This source PDF is a pure scan with no text layer at all, so every table here was read directly from the page images, not extracted text. This is a different tool from the existing Fire Water Demand calculator (OISD-116/API RP 2021) — that one computes bulk cooling/foam water volume; this one sizes the foam chamber/outlet layout itself. They use different bases and aren't meant to be summed. Alcohol-resistant foam requirements for fixed discharge outlets (Table 5.2.5.3.4) were referenced by the standard but not independently verified here — consult that table directly if you're protecting water-soluble/polar-solvent contents with fixed outlets.
Identification
Research entries stay private to you for practice/testing. Switch to Official once this is a real design your company should see.
Tank Type & Units
Number of Fixed Foam Discharge Outlets (Table 5.2.5.2.1)
Result
Minimum number of discharge outlets—
Discharge Rate & Time — Fixed Outlets (Table 5.2.5.2.2, Type II)
If your apparatus delivers more than the minimum rate, §5.2.5.2.3 permits a proportionate reduction in discharge time, down to a floor of 70% of the minimum time.
Monitor nozzles may serve as primary protection for cone roof tanks under semi-fixed system conditions (§5.2.4.1.1). Handlines are not permitted as primary protection for tanks over 30 ft (9 m) diameter or 20 ft (6.1 m) height (§5.2.4.1.2).
Result (same hydrocarbon type as above)
Minimum application rate—
Minimum discharge time—
Handline eligibility (§5.2.4.1.2)—
Seal Protection — Top-of-Seal Fixed Discharge Outlets (Table 5.3.5.3.1)
Applies to mechanical shoe seals, tube seals with metal weather shield, and metal or combustible secondary seals — all use the same rate/time in this table, differing only in the illustration detail referenced.
Result
Tank circumference—
Maximum spacing between outlets—
Minimum number of discharge outlets—
Minimum application rate0.3 gpm/ft² (12.2 mm/min)
Minimum discharge time20 minutes
Seal/Rim Area Water Demand (optional)
Result
Foam solution demand—
Note (§5.3.3.1): subsurface and semisubsurface injection shall NOT be used for open-top or covered floating roof tanks, due to the possibility of improper foam distribution at the fuel surface caused by the floating roof.