Under 49 CFR 180.407, what is the standard periodic pressure retest interval that applies to most DOT specification cargo tanks, unless a specific exception applies?

49 CFR 180.407(c)

Knowing the standard interval lets you tell when a tanker is legitimately operating under a shorter or longer exception versus actually overdue. A tank with an expired pressure retest is one of the first things a roadside inspector checks, and operating one can put the tank out of service.