Road Trailer Identification Chart*

WARNING: Road trailers may be jacketed, the cross section may look different than shown and exteral ring stiffeners would be invisible.

NOTE: An emergency shut-off valve is commonly found at the front of the tank, near the driver door.

For liquefied compressed gases (e.g., LPG, ammonia)
Rounded heads
Design pressure between 100-500 psi^**
Different configurations exist

For refrigerated liquefied gases (cryogenic liquids)
Similar to a "giant thermo-bottle"
Fitting compartments located in a cabinet at the rear of the tank
MAWP between 25-500 psi^**

For toxic, corrosive, and flammable liquids
Circular cross-section
May have external ring stiffeners
MAWP of at least 25 psi^**

For flammable liquids (e.g., gasoline, diesel)
Elliptical cross-section
Rollover protection at the top
Bottom outlet valves
MAWP between 3-5 psi (US + Mexico: MC306, DOT406, SCT306/406)
MAWP between 3-15 psi (Canada: TC306/406)

Usually for corrosive liquids
Circular cross-section
External ring stiffeners
Tank diameter is relatively small
MAWP of at least 15 psi^**

For emulsion and water-gel explosives
Hopper-style configuration
MAWP between 5-15 psi^**

For pressurized gases (e.g., air, helium, oxygen)
Long horizontal tubes permanently mounted on a trailer
Filling and discharge manifold typically located at the rear of trailer

For dry bulk cargo (e.g., oxidizers, corrosive solids, cement, plastic pellets, fertilizers)
Also known as hopper tanks or hopper trailers
Shape can vary but always contains one or more cone shaped bins

For cleanup of chemical/oil spills or for hauling crude oil, water
Working pressure may range from 20 to 500 psi
Large hinged rear door used for dumping

For general freight that carry bulk or non-bulk packages
May transport hazardous materials/ dangerous goods in small packages (e.g., bags, boxes, drums) or intermediate bulk containers (IBCs), sometimes referred to as “totes"
Cargo door(s) in the rear

For liquefied compressed gases, refrigerated liquefied gases, solids and liquids
Working pressure may range from 20 to 500 psi
Tank capacity can range from 50 to 12,000 gallons (200 to 45,000 L), and tank dimensions may vary

CAUTION: This chart depicts only the most general shapes of road trailers. Emergency response personnel must be aware that there are many variations of road trailers, not illustrated above, that are used for shipping chemical products. The suggested guides are for the most hazardous products that may be transported in these trailer types.

* The recommended guides should be considered as last resort if the material cannot be identified by any other means.