CFRT in High Pressure Cylinders

Natural gas powers roughly 15.2 million vehicles worldwide. Natural gas vehicles (NGVs) are good choices for high-mileage, centrally fueled fleets. In many cases, CNG can provide adequate range for the required vehicle application. The advantages of natural gas as a transportation fuel include its domestic availability, widespread distribution infrastructure, and reduced greenhouse gas emissions compared to conventional gasoline and diesel fuels.


There are mainly three types of NGVs:

Dedicated: These vehicles are designed to run only on natural gas.

Bi-fuel: These vehicles have two separate fueling systems that enable them to run on either natural gas or gasoline.

Dual-fuel: These vehicles have fuel systems that run on natural gas but use diesel fuel for ignition assistance. This configuration is traditionally limited to heavy-duty vehicles.

Light-duty vehicles are typically equipped with dedicated or bi-fuel systems, while heavy-duty vehicles use dedicated or dual-fuel systems. CNG vehicles store natural gas in tanks where it remains in the gaseous state.


High pressure cylinders used in automobiles are usually divided into 5 types:

Type 1 Cylinders

Type 1 CNG high pressure cylinders are all metal tanks made either from aluminum or steel.  They are the most affordable and the heaviest of all CNG tanks with lowest fuel capacities.


Type 2 Cylinders

Type 2 tanks are manufactured with a metal liner reinforced by glass or carbon fiber composite wrap around the middle; also referred to as “hoop wrap”.  The liner and composite each receive 50% of the stress caused by internal pressurization.  These high pressure cylinders are lighter and carry higher capacities than type 1 CNG cylinders, but cost more.


Type 3 Cylinders

Like Type 2, are manufactured by a metal liner, however, reinforced with a full composite wrap covering the entire tank. The full composite wrap absorbs most of the gas pressure. Type 3 high pressure cylinders are even lighter and carry higher capacity than Type 2 CNG tanks. Of course, they are also more expensive.


Type 4 Cylinders

Type 4 CNG Tanks are manufactured by a plastic gas-tight liner reinforced by a full composite wrap around entire tank.  The entire strength of the tank is composed of composite reinforcement tape.  Type 4 high pressure cylinders provide higher capacity and are lighter than the Type 3 CNG tanks. However, they are the most expensive of all tank types.


Type 5 Cylinders

Type 5 is different from the other carbon fiber tanks in that it is a liner-less fully glass fiber composite tank.  These tanks are lighter and more affordable whose capacity are 16%-20% more than other composite cylinder tanks on the market.


Continuous Fiber Reinforced Thermoplastic Composites made by TOPOLO can be used mainly in 3 types of these tanks: Type 2, Type 3 and Type 4 tanks. The new material strengthens CNC tanks by means of:

Seamless aluminum liner

Excellent impact tolerance

Great heat tolerance

Light weight

Cost efficiency