CFR › Title 46 › Part 154 › §154.55046 CFR §154.550Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗Copy linkIf the excess flow valve allowed under § 154.532(b) has a bypass, the bypass must be of 1.0 mm (0.0394 in.) or less in diameter.