StacksVerified U.S. regulatory reference

46 CFR §153.407

Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗
  1. (a)A sounding tube installed as a restricted gauge must extend to within one meter (approx. 39.4 in.) of the bottom of the tank.
  2. (b)A sounding tube must not be installed on a tank whose relief valve setting exceeds 28 kPa (approx. 4 psig) unless it is specifically permitted by the Commandant (CG-ENG).
  3. (c)A sounding tube must have no perforations in the tube wall.