Table 32 to Subpart G of Part 63—Typical Number of Roof Legs,
a NF8
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.