1960 U.S. Steel DOT 107A Tube Trailer – 2400 PSI MAWP – 180 CU FT (5097 Liters)

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

This trailer was retested in February 2023 by TEA Technologies using ASTM E 1419-02b and ASTM E 2223-02 acoustic emission and ultrasonic methods, with the next retest due in February 2028. DOT 107A tube trailers typically require requalification every five years, though the interval depends on the specific CFR requirements and any state or insurance mandates that may apply to your operation.

What is the actual gas capacity at service pressure?

The listing states a total water volume of 180 cubic feet (5,097 liters) and a MAWP of 2,400 PSI, but does not provide the actual gas capacity at working pressure. To calculate storage capacity for your gas, ask the seller for the number of tubes, individual tube volumes, and the specific working pressure you intend to operate at—then apply the compressibility factor for your gas of interest.

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

The listing describes it as suitable for inert gases including nitrogen, helium, argon, or compressed air, but does not specify what service it has actually been in. Ask the seller for the complete service history, as previous contents dictate cleaning and purging requirements—oxygen service conversion, for example, requires rigorous degreasing and certification, while switching between dry inert gases is typically straightforward.

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

Verify the retest documentation is complete and that all tube serial numbers match the certification paperwork, then visually inspect for external corrosion, road rash, and frame cracks especially near tube mounts and suspension points. Check all valves, manifolds, and pigtails for leaks and operability, examine tire condition and brake function, and confirm the DOT certification plate is legible and intact. On a 1960-vintage unit, pay close attention to tube-to-manifold connections and any signs of previous repair welds, as fatigue cracking becomes more likely with age.