StacksVerified U.S. regulatory reference

40 CFR Part 63, Table 26

Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov
Seal typeKSn
Liquid mounted resilient seal:
Primary seal only30
With rim-mounted secondary seal a1.60
Vapor mounted resilient seal:
Primary seal only6.70
With rim-mounted secondary seal a2.50

a If vessel-specific information is not available about the secondary seal, assume only a primary seal is present.