StacksVerified U.S. regulatory reference

40 CFR Part 63, Table 27

Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov
Deck fitting typeDeck fitting loss factor (KF) aTypical number of fittings (NF)
Access hatch| 1
Bolted cover, gasketed1.6
Unbolted cover, gasketed11
Unbolted cover, ungasketedb 25
Automatic gauge float well| 1
Bolted cover, gasketed5.1
Unbolted cover, gasketed15
Unbolted cover, ungasketedb 28
Column well| (see Table 24).
Builtup column-sliding cover, gasketed33
Builtup column-sliding cover, ungasketedb 4710
Pipe column-flexible fabric sleeve seal19
Pipe column-sliding cover, gasketed32
Pipe column-sliding cover, ungasketed
Ladder well| 1
Sliding cover, gasketed56
Sliding cover, ungasketedb 76
Roof leg or hanger well| (5 + D/10 + D 2/600) c.
Adjustableb 7.9
Fixed0
Sample pipe or well| 1
Slotted pipe-sliding cover, gasketed44
Slotted pipe-sliding cover, ungasketed57
Sample well-slit fabric seal, 10 percent open areab 12
Stub drain, 1-in diameter d1.2(D 2/125) c.
Vacuum breaker| 1
Weighted mechanical actuation, gasketedb 0.7
Weighted mechanical actuation, ungasketed0.9

a Units for KF are pound-moles per year.

b If no specific information is available, this value can be assumed to represent the most common/typical deck fittings currently used.

c D = Tank diameter (feet).

d Not used on welded contact internal floating decks.