Section 179.12 - Interior heater systems(a) Interior heater systems shall be of approved design and materials. If a tank is divided into compartments, a separate system shall be provided for each compartment.(b) Each interior heater system shall be hydrostatically tested at not less than 13.79 bar (200 psig) and shall hold the pressure for 10 minutes without leakage or evidence of distress.Amdt. 179-52, 61 FR 28678, June 5, 1996, as amended by 66 FR 45390 , Aug. 28, 2001