40 CFR Part 63, Table 3
Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗
| If the storage vessel capacity (gallons) is . . . | And the vapor pressure a (psia)is . . . | Then, you must use the following type of storage vessel . . . |
|---|---|---|
| ≥20,000 but <40,000 | ≥4 | Internal floating roof, external floating roof, or fixed roof vented to a closed vent system and control device achieving 95 percent reduction.b |
| ≥40,000 | ≥0.75 | Internal floating roof, external floating roof, or fixed roof vented to a closed vent system and control device achieving 95 percent reduction.b |
| Any capacity. | >11.1 | Pressure vessel.c |
| All other capacity and vapor pressure combinations | Fixed roof.d |
a Maximum true vapor pressure of total HAP at storage temperature.
b If using a fixed roof storage vessel vented to a closed vent system and control device, you must meet the requirements in § 63.11910(a) for fixed roof storage vessels. If using an internal floating roof storage vessel or external floating roof storage vessels, you must meet the requirements in § 63.11910(b) for internal floating roof storage vessels or external floating roof storage vessels, as applicable.
c Meeting the requirements of § 63.11910(c) for pressure vessels.
d Meeting the requirements in § 63.11910(a) for fixed roof storage vessels.