Table 30 to Subpart G of Part 63—Roof Fitting Loss Factors, KFa, KFb, and m, a and Typical Number of Fittings, NT

- Table 30 to Subpart G of Part 63—Roof Fitting Loss Factors, KFa, KFb, and m, a and Typical Number of Fittings, NT

Fitting type and construction details	Loss factors b			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	c 0		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	c 0.98		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	c 1.0		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	c 1.0		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	c 1.0		Weighted mechanical actuation, ungasketed	1.2	3.0	1.0		Roof drain (3-in-diameter)				NF7 (Table 31).	Open	0	7.0	e 1.4	NF8 (Table 32 f).	90 percent closed	0.51	0.81	1.0		Roof leg (3-in-diameter)				NF8 (Table 32 f).	Adjustable, pontoon area	1.5	0.20	c 1.0		Adjustable, center area	0.25	0.067	c 1.0		Adjustable, double-deck roofs	0.25	0.067	1.0		Fixed	0	0	0		Roof leg (2 1/2-in-diameter)				NF8 (Table 32 f).	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)				1 g.	Weighted mechanical actuation, gasketed	0.71	0.10	c 1.0		Weighted mechanical actuation, ungasketed	0.68	1.8	1.0

a The roof fitting loss factors, KFa, KFb, and m, may only be used for wind speeds from 2 to 15 miles per hour.

b Unit abbreviations are as follows: lb = pound; mi = miles; hr = hour; yr = year.

c If no specific information is available, this value can be assumed to represent the most common or typical roof fittings currently in use.

d A slotted guide-pole/sample well is an optional fitting and is not typically used.

e Roof 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.

f The most common roof leg diameter is 3 inches. The loss factors for 2 1/2-inch diameter roof legs are provided for use if this smaller size roof is used on a particular floating roof.

g Rim vents are used only with mechanical-shoe primary seals.