Fiba 40ft UN DOT Style Cryogenic Storage — 91.0 gal, 3169 PSIG

Is this ASME or DOT rated, and what does that allow me to do with it?

This vessel carries UN DOT style certification, which qualifies it for both transport and stationary use with inert gases. DOT-rated vessels are subject to periodic requalification intervals and typically face restrictions on the service fluids compared to ASME Section VIII vessels, but the transport authorization is the defining advantage. Confirm with the seller whether current DOT markings and stamping are legible and whether a valid hydrostatic test date is present.

What is the MAWP and capacity at service pressure?

The listing states a working pressure of 3169 PSIG with 91.0 gallon capacity. For DOT cylinders, working pressure and MAWP are typically the same unless the vessel has been derated, but verify the nameplate stamping matches these figures. The 40-foot length suggests this is a tube trailer or stationary tube bank assembly, so confirm whether the 91.0 gallons refers to a single tube or the aggregate capacity of the bundle.

What is the requalification or inspection status?

The listing does not state the last hydrostatic test date or requalification status. DOT cylinders in high-pressure inert gas service typically require requalification every 5 or 10 years depending on the specification (3AA, 3AAX, or others), so request documentation showing the most recent test date, serial numbers, and stamped markings. If the unit is out of qualification, factor retesting and potential rejection risk into your evaluation.

What should I inspect before putting it into service?

Verify all nameplate data, serial numbers, and DOT specification markings are legible and match the hydrostatic test documentation. Inspect valve threads, manifold piping, relief devices, and support cradles for corrosion, impact damage, or signs of over-pressurization such as bulging or weld cracks. DOT tubes are often subject to internal corrosion if moisture ingress occurred during storage, so a visual internal inspection through valve ports is recommended if accessible, and hydrostatic requalification should be planned if the last test date is unknown or approaching the interval limit.