3,855 PSI, Type 1, 40-foot High Pressure Trailer for CNG, Hydrogen, Nitrogen Service

What is the requalification status, and when is the next test due?

The tanks are currently out of DOT certification and cannot be used for transportation until recertified. The chassis has a current DOT inspection as of November 2024. DOT-E 8008 exemption cylinders typically require requalification every 3 or 5 years depending on the specific exemption terms, but you'll need to verify the interval and last test date with the seller to determine how long they've been out of service.

What is the actual gas capacity at service pressure?

At the 3,855 PSIG maximum allowable working pressure, this trailer holds 113,000 SCF of CNG, 99,700 SCF of oxygen, 99,400 SCF of argon, 87,000 SCF of nitrogen, 82,600 SCF (193 KG) of hydrogen, or 86,000 SCF of helium. The water volume is 363.1 cubic feet.

What gas service has it been in, and what can it be converted to?

This trailer was previously used in CNG service. After DOT recertification, it can be configured for hydrogen, nitrogen, or CNG service. Steel Type 1 trailers like this can typically handle most industrial gases, but previous CNG service usually means minimal contamination concerns for inert gases; verify with the seller whether any modifications beyond recertification are needed for your intended gas.

What should I inspect on a used tube trailer before buying?

Check the tube exterior for corrosion, gouges, and arc strikes that could affect recertification, and verify all nameplates and DOT markings are legible. Inspect the chassis for structural rust, brake condition, tire age, and function of all valves and manifold components. The empty cabinet mentioned in this listing should be checked for rust-through if you plan to use it for storage. Most importantly, confirm the DOT exemption number is still active and that tubes of this age can still be requalified—some older exemptions have been discontinued.