33 C.F.R. § 183.558
(b) Each hose used—
(1) For a vent line or fill line must be:
(ii) “USCG Type B1” or “USCG Type B2” if no more than five ounces of fuel is discharged in 2 1/2 minutes when:
(2) From the fuel tank to the fuel inlet connection on the engine must be:
(ii) “USCG Type B1” if no more than five ounces of fuel is discharged in 2 1/2 minutes when:
(c) Each hose must be secured by:
(d) The inside diameter of a hose must not exceed the actual minor outside diameter of the connecting spud, pipe, or fitting by more than the distance shown in Table 8.
| If minor outside diameter of the connecting spud, pipe, or fitting is— | The inside diameter of the hose must not exceed the minor outside diameter of the connecting spud, pipe, or hose fitting by more than the following distance: |
| Less than 3⁄8 in | 0.020 in. |
| 3⁄8 in. to 1 in | 0.035 in. |
| Greater than 1 in | 0.065 in. |
[CGD 74-209, 42 FR 5950, Jan. 31, 1977, as amended by CGD 85-098, 52 FR 19728, May 27, 1987]