CNG cylinders are divided into four categories

The first is steel or aluminum alloy metal bottle (CNG-1);

The second type is the composite gas cylinder (CNG-2) with steel or aluminum lining and body reinforced by "hoop winding" resin impregnated long fiber;

The third is the composite gas cylinder (CNG-3) reinforced with steel or aluminum lining and "integral winding" resin impregnated long fiber;

The fourth type is the composite gas cylinder (CNG-4) reinforced with plastic lining and "integral winding" resin impregnated long fiber.

These gas cylinders have their own advantages and disadvantages, and can be selected according to different vehicle types.

At present, steel cylinders are mainly used in China, and their performance must meet the requirements of GB17258 Compressed Natural Gas Cylinders for Vehicles. Generally, high-quality chromium-molybdenum steel is used as the cylinder material.