Used Cryogenic Trailers & Transports for Sale

It's a vacuum-insulated trailer, an inner vessel inside an outer jacket, that hauls liquefied gases such as LIN, LOX, LAR, LNG, LH2 and CO2. In the U.S., trailers for these cryogenic liquids are built to the DOT MC-338 specification, and many unload by pressure transfer using onboard pressure-building coils. Refrigerated liquid CO2 falls under a separate DOT section with its own rules.

Sources: 49 CFR 178.338-1 · Chart cryogenic transport trailers · 49 CFR 173.315

It's a trailer-mounted unit that combines a liquid nitrogen tank, a triplex cryogenic pump and a vaporizer to deliver high-pressure nitrogen gas where it's needed. Vaporizers are direct-fired or heat-recovery types. The same equipment comes skid- or truck-mounted, and one manufacturer lists discharge pressures up to 10,000–15,000 psi.

Source: NOV nitrogen products brochure

It's a UN portable tank for refrigerated liquefied gases: more than 450 liters, a steel shell with vacuum or foam insulation inside a jacket, in a frame for intermodal moves. Each gas it carries has its own reference holding time set by type testing. Tanks for flammable gases need three independent shut-off devices; non-flammable need two.

Source: 49 CFR 178.277

Start with the inspection and test dates and when the next ones are due. Then check the vacuum: cold spots, frost or sweating on the jacket, or unusually fast pressure build-up point to vacuum loss, and the manufacturer can advise on testing. After that, check the chassis and brakes, any pump and piping, the relief devices, and the last product carried.

Sources: 49 CFR 180.407 · Chart delivery tanks manual · 49 CFR 396.17

MC-338 trailer: an external visual inspection every year and a pressure test every 5 years, at 1.25 times MAWP or re-rated pressure. A tank out of hazmat service a year or more must be tested before use. Cryogenic ISO tank: an intermediate inspection at least every 2.5 years and a full one at least every 5. Chassis: its own annual DOT inspection.

Sources: 49 CFR 180.407 · 49 CFR 180.605 · 49 CFR 396.17

MRHT is how long a loaded tank can hold its product before the relief valves would vent; the spec plate lists it for at least one named liquid. For flammable cryogenic liquids such as LNG, it sets the one-way travel time marked on the jacket. If actual holding time falls below 90% of MRHT, the tank can't be refilled until it's restored or re-marked, so a weak holding time limits range.

Sources: 49 CFR 173.318 · 49 CFR 178.338-18

Get the spec plate data (MAWP, design temperature range, MRHT, whether it's insulated for oxygen service), the inspection and test records, the title and chassis documents, and the prior product history. Changing product depends on the manufacturer, so contact them before switching. A tank can't be loaded with a liquid colder than its design service temperature. On LNG specifically: that call is ours, not something the sources below set — we treat trailers built for LNG as staying in LNG service.

Sources: 49 CFR 178.338-18 · 49 CFR 173.318 · 49 CFR 180.407