GroundRules
40 CFR Table 32 to Subpart G of Part 63: Table 32 to Subpart G of Part 63—Typical Number of Roof Legs, a NF8
Where this section sits in the code
- Title 40—Protection of Environment
- CHAPTER I—ENVIRONMENTAL PROTECTION AGENCY
- SUBCHAPTER C—AIR PROGRAMS
- PART 63—NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES
- Subpart G—National Emission Standards for Hazardous Air Pollutants From the Synthetic Organic Chemical Manufacturing Industry for Process Vents, Storage Vessels, Transfer Operations, and Wastewater
Tank diameter D (feet) b Pontoon roof No. of legs on double-deck roof
No. of pontoon legs No. of center legs
30 4 2 6
40 4 4 7
50 6 6 8
60 9 7 10
70 13 9 13
80 15 10 16
90 16 12 20
100 17 16 25
110 18 20 29
120 19 24 34
130 20 28 40
140 21 33 46
150 23 38 52
160 26 42 58
170 27 49 66
180 28 56 74
190 29 62 82
200 30 69 90
210 31 77 98
220 32 83 107
230 33 92 115
240 34 101 127
250 34 109 138
260 36 118 149
270 36 128 162
280 37 138 173
290 38 148 186
300 38 156 200
310 39 168 213
320 39 179 226
330 40 190 240
340 41 202 255
350 42 213 270
360 44 226 285
370 45 238 300
380 46 252 315
390 47 266 330
400 48 281 345
a This table should not supersede information based on actual tank data.
b If the actual diameter is between the diameters listed, the closest diameter listed should be used. If the actual diameter is midway between the diameters listed, the next larger diameter should be used.
Collected 2026-08-27T02:26:04Z. Source file · JSON