* 3.16 Tank body and equipment, type I and type II. The semitrailer shall be designed and
constructed for the legal transportation by interstate carriers of liquid corrosive materials of the
types specified (see 6.2). Accordingly, the semitrailer shall conform to the regulations of the
Department of Transportation (DoT) governing the transportation of the specified corrosive
materials in tank motor vehicles. Conformance to DoT Safety Regulation 178.345 and DoT
Safety Regulation 178.348, Specification DoT-412, as published in the latest issues of the Code
of Federal Regulations and as modified by all issues of the Federal Register published and in
effect prior to completion of the semitrailer shall be total and without exception or exemption.
Tank marking shall be in accordance with all the applicable portions of DoT Safety Regulations
171 through 178 for hazardous material.
* 3.16.1 Material. The tank and all its associated components, saddles, pads and
appurtenances shall be fabricated of type 316L stainless steel, suitable for handling liquids of the
types specified (see 6.2). The tank and the lining, when furnished, shall meet the requirements of
DoT Safety Regulation 178.345-2, without repair or replacement, with a thinning by corrosion
allowance sufficient for a 10 year normal service life of the vehicle. The top of the fenders, the
flashing boxes, and the exterior tank discharge and intake pipe areas shall be of type 316L
stainless steel. Gaskets and seals shall be of suitable material to withstand attack by the tank
contents. When specified (see 6.2), in addition, all tank surfaces exposed to the specified liquids
during loading, unloading and transportation shall be completely covered with natural rubber
lining, synthetic rubber ("Hypalon") lining or polyester (type 64) lining, as appropriate to the
type of liquids specified. The lining material shall be not less elastic than the material of the tank
proper and shall be leakproof. When lining is furnished the lining material shall also be applied
to the exterior tank section at the flashing boxes and on top of the rear fenders.
3.16.2 Capacity. The liquid capacity of the tank shall conform to 1.2.2 for the specified size
of vehicle, plus at least 3 percent for expansion. The tank shall have a single compartment.
220.127.116.11 Capacity marker. A graduated capacity marker or indicator of corrosion resistant
construction shall be installed in a location readily visible from the operator's normal position
during loading operations.
* 3.16.3 Tank configuration. The tank shall be cylindrical or round in cross section with
external ring stiffeners.
3.16.4 Design pressure. The tank shall be designed and constructed to be unloaded by an
internal pressure of not less than 35 pounds per square inch gage (psig).
3.16.5 Product density. The tank shall be designed and constructed to transport liquids with
a density of up to 13 pounds per gallon.