Code of Federal Regulations > Title 40 > Chapter I > Part 63 > Subpart G > Appendix - Table 32 to Subpart G of Part 63

Regulations last checked for updates: May 18, 2024

Title 40 - Protection of Environment last revised: May 16, 2024

Appendix - 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
Tank diameter D (feet) ^b	No. of pontoon legs	No. of center legs	No. of legs on double-deck roof
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.

authority: 42 U.S.C. 7401

source: 57 FR 61992, Dec. 29, 1992, unless otherwise noted.