33 CFR § 183.586 - Pressure impulse test.
A fuel tank is tested by performing the following procedures in the following order:
(a) Perform the static pressure test under § 183.580.
(b) If the tank is non-metallic, fill it to capacity with a gasoline that has at least a 50 percent aromatic content. Keep the fuel in the tank at 21 °C or higher for 30 days prior to testing.
(c) Mount the tank on a test platform.
(d) Fill the tank to capacity with water.
(e) Cap and seal each opening in the tank.
(f) Apply 25,000 cycles of pressure impulse at the rate of no more than 15 impulses per minute varying from zero to three PSIG to zero inside the tank top from a regulated source of air, inert gas, or water.
(g) Perform the static pressure test under § 183.580.