CNG Tank - DOT Carbon Fiber (Type 4) 3600 psi ( Brand New) 21x80 35GGE Capacity

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

This tank is DOT rated under FMVSS 304 and NGV2 certified, which qualifies it for on-vehicle use in natural gas vehicles and mobile CNG applications. DOT cylinders are designed for transportation and vehicular service, not stationary storage like ASME vessels.

What is the MAWP and capacity at service pressure?

The maximum allowable working pressure is 3600 psi, and the capacity at service pressure is 35 GGE (gasoline gallon equivalent). The physical dimensions are 21 inches in diameter by 80 inches in length.

What is the requalification or inspection status?

The listing states the tank is brand new and never used with 10+ years of remaining life. Type 4 CNG cylinders typically require inspection every 3 or 5 years depending on jurisdiction and vehicle type, so verify the current hydrostatic test date stamped on the neck and confirm the applicable inspection interval for your intended use.

What should I inspect before putting it into service?

Even though the listing describes this as new and never installed, inspect the aluminum liner neck for the original hydrostatic test date and serial number, verify all markings are legible, and check the valve threads and O-ring sealing surfaces for damage during storage or handling. On Type 4 cylinders, visually inspect the carbon fiber overwrap for any gouges, abrasion, or UV degradation if it has been stored outdoors, and confirm the PRD (pressure relief device) is present and undamaged.