Code of Federal Regulations Title 49. Transportation § 49.178.337–6 Closure for manhole

(a) Each cargo tank marked or certified after April 21, 1994, must be provided with a manhole conforming to paragraph UG–46(g)(1) and other applicable requirements in Section VIII of the ASME Code (IBR, see § 171.7 of this subchapter), except that a cargo tank constructed of NQT steel having a capacity of 3,500 water gallons or less may be provided with an inspection opening conforming to paragraph UG–46 and other applicable requirements of the ASME Code instead of a manhole.

(b) The manhole assembly of cargo tanks constructed after June 30, 1979, may not be located on the front head of the cargo tank.