CNG, or Compressed Natural Gas, has emerged as an immensely popular and sustainable fuel due to its lower cost and lesser carbon emissions compared to other common fuels like diesel and petrol. The role of type 3 cylinder suppliers is also increasing as petrol and diesel prices continue to soar. Since this switch is growing faster than expected, it is better to know more about the different types of CNG cylinders on offer.

 

Compressed natural gas can expand and contract depending upon the temperature, and thus, the amount of CNG that a vehicle can hold is dependent on many factors like the ambient temperature, fuelling rate, tank type and pressure rating. CNG tanks are classified into four types, Type 1, Type 2, Type 3, and Type 4, which are primarily determined on the basis of design, liner material, and production method. The Type 1 cylinders are made of steel, are heavier and thus, add more weight to the vehicles. Type 3 and 4 are fully wrapped composite cylinders with metal and plastic liners, respectively, and are much lighter than Type 1. Let us see more about Type 3 CNG cylinders.

 

Type 3 cylinders suppliers provide tanks that consist of a thin, lightweight aluminum liner completely covered with a carbon composite. They provide significant weight savings over Type 2 cylinders and can also be filled to high pressures. Hence, they offer increased capacity for cylinders of similar size. Such cylinders are ideal for applications where capacity and portability are important. Some of their applications include home oxygen therapy, portable field testing, ambulatory oxygen, fuel cell applications, drone/UAVs, calibration, aerospace and military. 

 

Why Are They A Safer Alternative?

Impact Tolerance

The composite at the inner surface of the Type 3 cylinders provides 75 to 90% of the vessel's strength. The liner offers the rest of the strength, which also acts as a rigid membrane, resistant to damage caused by impact events. It also mitigates the risk of composite flexing and subsequent leakage. Hence, type 3 cylinders are a better alternative than Type 4 due to their higher resistance to damage. 

Seamless Aluminium Liner

As the temperature of the gas increases due to the heat of compression in tanks, the tank may not be filled to its full capacity when the gas is at an elevated temperature. Also, the fast fill process results in more heat, leaving the storage space underutilized, and the aluminum liner can conduct the gas away from the internal storage space. Hence, these cylinders facilitate better heat absorption resulting in optimum use of the tank's storage capacity. Since Type 3 cylinders are devoid of any welds or joints, they are characterized by gas-tight construction with zero permeability. 

Heat Tolerance

As the Type 3 cylinders have greater heat resistance, they are able to achieve greater fill. Its composite fibers are held intact by the liners, which do not wear away and succumb to heat. This ensures that the tank has a high degree of heat tolerance, which is of great quality.

Burst Safety Factor

These cylinders are the safest alternative as the aluminum liners in Type 3 cylinders have high corrosion resistance despite aggressive components in Natural gas. These cylinders are built with burst safety factors to ensure maximum safety for CNG vehicles and passengers. Since Type 3 CNG cylinders have a 'leak before burst' feature, they provide excellent safety while offering better fast fill performance. 

Better Fast-Filling Efficiency

Type 3 cylinders are superior to Type 4 in terms of fast filling performance, resulting in rapid heat generation, leaving less time to conduct the heat away. Fast filling performance leads to a miscalculation of the cylinder's fuel capacity as the CNG in the tank since the CNG molecules expand due to the heat generated by the rapid movement and compression of CNG in the cylinders. Hence, Type 3 CNG cylinders are the best choice due to their fast filling efficiency as the linear conduits heat to Pressure Relief Devices. Also, the aluminum liner in these cylinders has high thermal conductivity, which helps achieve a complete fill even during fast fill operations. 

To Sum Up

Apart from the above benefits, type 3 cylinders are made of high-strength carbon fiber and epoxy composite and provide weight-efficient gas storage. Since the aluminum helps dissipate the heat, the cylinder can accommodate a larger mass of gas, thus significantly improving the driving range without affecting the vehicle's gross weight. Therefore, we can conclude that Type 3 CNG cylinders offer a wide range of benefits, being lightweight, durable, safer and a better alternative to other CNG cylinder types.