46 C.F.R. § 64.83 – Hydrostatic test.

(a) The hydrostatic test required in § 64.77(c) includes—
1. (1) Closing each manhole and other openings by normal means of closure;
2. (2) Using wrenches or other tools that are used during normal operations to close the manhole and other openings;
3. (3) Using the same type of gaskets as used in service;
4. (4) If required for the inspection, removing tank insulation;
5. (5) Filling the tank with water and pressurizing to the test pressure indicated on the metal identification plate without leaking; and
6. (6) If fitted with an internal heating coil, the heating coil passing a hydrostatic test at a pressure of 200 psig or more or 50 percent or more above the rated pressure of the coil, whichever is greater.
(b) If the tank passes the hydrostatic test required in paragraph (a) of this section, the owner or his representative may stamp the date of the test and his initials on the metal identification plate required in § 64.53.