| Fitting type and construction details | Loss factorsb | Typical number of fittings, NT | ||
|---|---|---|---|---|
| KFa (lb-mole/yr) | KFb (lb-mole/[mi/hr]m-yr) | m (dimensionless) | ||
| Access hatch (24-in-diameter well) | 1. | |||
| Bolted cover, gasketed | 0 | 0 | c0 | |
| Unbolted cover, ungasketed | 2.7 | 7.1 | 1.0 | |
| Unbolted cover, gasketed | 2.9 | 0.41 | 1.0 | |
| Unslotted guide-pole well (8-in-diameter unslotted pole, 21-in-diameter well) | 1. | |||
| Ungasketed sliding cover | 0 | 67 | c0.98 | |
| Gasketed sliding cover | 0 | 3.0 | 1.4 | |
| Slotted guide-pole/sample well (8-in-diameter unslotted pole, 21-in-diameter well) | (d). | |||
| Ungasketed sliding cover, without float | 0 | 310 | 1.2 | |
| Ungasketed sliding cover, with float | 0 | 29 | 2.0 | |
| Gasketed sliding cover, without float | 0 | 260 | 1.2 | |
| Gasketed sliding cover, with float | 0 | 8.5 | 1.4 | |
| Gauge-float well (20-inch diameter) | 1. | |||
| Unbolted cover, ungasketed | 2.3 | 5.9 | c1.0 | |
| Unbolted cover, gasketed | 2.4 | 0.34 | 1.0 | |
| Bolted cover, gasketed | 0 | 0 | 0 | |
| Gauge-hatch/sample well (8-inch diameter) | 1. | |||
| Weighted mechanical actuation, gasketed | 0.95 | 0.14 | c1.0 | |
| Weighted mechanical actuation, ungasketed | 0.91 | 2.4 | 1.0 | |
| Vacuum breaker (10-in-diameter well) | NF6 (Table 31). | |||
| Weighted mechanical actuation, gasketed | 1.2 | 0.17 | c1.0 | |
| Weighted mechanical actuation, ungasketed | 1.2 | 3.0 | 1.0 | |
| Roof drain (3-in-diameter) | NF7 (Table 31). | |||
| Open | 0 | 7.0 | e1.4 | NF8 (Table 32f). |
| 90 percent closed | 0.51 | 0.81 | 1.0 | |
| Roof leg (3-in-diameter) | NF8 (Table 32f). | |||
| Adjustable, pontoon area | 1.5 | 0.20 | c1.0 | |
| Adjustable, center area | 0.25 | 0.067 | c1.0 | |
| Adjustable, double-deck roofs | 0.25 | 0.067 | 1.0 | |
| Fixed | 0 | 0 | 0 | |
| Roof leg (21⁄2 -in-diameter) | NF8 (Table 32f). | |||
| Adjustable, pontoon area | 1.7 | 0 | 0 | |
| Adjustable, center area | 0.41 | 0 | 0 | |
| Adjustable, double-deck roofs | 0.41 | 0 | 0 | |
| Fixed | 0 | 0 | 0 | |
| Rim vent (6-in-diameter) | 1g. | |||
| Weighted mechanical actuation, gasketed | 0.71 | 0.10 | c1.0 | |
| Weighted mechanical actuation, ungasketed | 0.68 | 1.8 | 1.0 | |
aThe roof fitting loss factors, KFa, KFb, and m, may only be used for wind speeds from 2 to 15 miles per hour.
bUnit abbreviations are as follows: lb = pound; mi = miles; hr = hour; yr = year.
cIf no specific information is available, this value can be assumed to represent the most common or typical roof fittings currently in use.
dA slotted guide-pole/sample well is an optional fitting and is not typically used.
eRoof drains that drain excess rainwater into the product are not used on pontoon floating roofs. They are, however, used on double-deck floating roofs and are typically left open.
fThe most common roof leg diameter is 3 inches. The loss factors for 21⁄2 -inch diameter roof legs are provided for use if this smaller size roof is used on a particular floating roof.
gRim vents are used only with mechanical-shoe primary seals.
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