StacksVerified U.S. regulatory reference

40 CFR Part 63, Table 29

Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov
Seal typeWelded vesselsRiveted vessels
KSNKS | N
Metallic shoe seal: | |
Primary seal only1.21.5 | 1.3 | 1.5
With shoe-mounted secondary seal0.81.2 | 1.4 | 1.2
With rim-mounted secondary seal0.21 | 0.2 | 1.6
Liquid mounted resilient seal: | |
Primary seal only1.11 | a NA | NA
With weather shield0.80.9 | NA | NA
With rim-mounted secondary seal0.70.4 | NA | NA
Vapor mounted resilient seal: | |
Primary seal only1.22.3 | NA | NA
With weather shield0.92.2 | NA | NA
With rim-mounted secondary seal0.22.6 | NA | NA

a NA = Not applicable.