120 GGE CNG Storge- 3 pack, Back fo the Truck, Type 4 cylinders, 26x80 (Capacity: 41.1 GGE / 489.1 Liters)

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

These are DOT-rated tanks manufactured to DOT on-road safety standards, which allows them to be used as mobile fuel storage on vehicles. DOT certification is required for CNG systems mounted on trucks and vehicles that travel public roads, while ASME is for stationary installations. The listing indicates these were removed from in-service Class 8 trucks and are suitable for tank replacements, dual-fuel retrofits, or new CNG/RNG vehicle builds.

What is the MAWP and capacity at service pressure?

The pressure rating is 3,600 PSI, which for DOT cylinders typically refers to the service pressure. Total capacity per three-tank package is 120 GGE (1,467.3 liters total), with each individual tank rated at 41.1 GGE (489.1 liters). The listing does not specify whether this capacity is stated at the full 3,600 PSI service pressure or a lower usable pressure, so confirm the capacity rating basis with the seller if your application requires precise fuel delivery calculations.

What is the requalification or inspection status?

The tanks were visually inspected upon removal and found to be in excellent condition, with approximately 10 years of service life remaining from their original 20-year design life. Manufacture years are 2013–2014. The listing mentions tanks can be re-certified for three additional years through DOT inspection, but does not state whether current certifications are in place or when the last formal DOT requalification was performed—ask the seller for documentation of the most recent inspection and cylinder manufacture dates stamped on each unit.

What should I inspect before putting it into service?

Verify the manufacture date stamped on each cylinder to confirm remaining service life, and inspect for impact damage, abrasion, or cuts in the carbon fiber composite overwrap, particularly at mounting points and the cylinder shoulder. Check all valves, pressure relief devices, and fittings for function and leaks, noting the listing states some fueling system components may be missing. On Type 4 cylinders, examine the boss area where the valve threads into the liner for cracks or damage, inspect for evidence of overpressure or fire exposure, and confirm the DOT requalification is current for your jurisdiction if putting these back into on-road service.