CNG Composite Cylinders

 CNG-2 cylinders, also known as Type 2 CNG composite cylinders, are a type of compressed natural gas (CNG) storage solution used in vehicles. These cylinders are designed with a steel or aluminum liner and are reinforced with fibers through a process called "hoop winding." This construction offers a balance between weight, cost, and performance.

Key Features and Specifications

Materials and Construction

• Liner Material: Typically made of steel (30CrMo or similar) or aluminum.
• Reinforcement: The cylinder's barrel is reinforced with long fibers (fiberglass or carbon fibers) impregnated with resin using a hoop winding technique. This reinforcement provides additional strength and reduces overall weight compared to all-steel cylinders.
• Manufacturing Standards: CNG-2 cylinders conform to standards such as ISO 11439:2013, GB/T 24160, and ECE R110, ensuring high safety and performance.

Technical Specifications

• Internal and External Diameters: Examples include an internal diameter (ID) of 325 mm and an external diameter (OD) of 334 mm.
• Volume: Cylinders come in various volumes, ranging from 45 liters to 120 liters.
• Length: The length of the cylinders (without the valve) ranges from 735 mm to 1691 mm, depending on the volume.
• Weight: Weight varies based on the size, with examples ranging from 36 kg to 85 kg.
• Wall Thickness: Typically around 4.6 mm.
• Working Pressure: Usually designed for a working pressure of 20 MPa (200 bar).

Applications

CNG-2 cylinders are designed for use in various types of vehicles, including:

• Light-Duty Vehicles: Cars and small vans benefit from the weight savings provided by composite cylinders.
• Medium and Heavy-Duty Vehicles: Buses and trucks that require larger volumes of CNG benefit from the strength and durability of these cylinders while maintaining a lower weight compared to all-steel cylinders.

Advantages of Type 2 CNG Composite Cylinders

• Reduced Weight: The composite reinforcement significantly reduces the weight of the cylinder compared to traditional all-steel cylinders, improving vehicle fuel efficiency and performance.
• High Strength: The hoop-wrapped fibers provide excellent strength, allowing the cylinders to withstand high pressures.
• Corrosion Resistance: The composite materials and resin coating help protect against corrosion, extending the cylinder's lifespan.
• Safety: Conformance to international safety standards (ISO 11439, ECE R110) ensures these cylinders are safe for high-pressure storage and use in automotive applications.

Suppliers and Standards

Numerous suppliers provide Type 2 CNG composite cylinders globally. These suppliers manufacture cylinders according to stringent standards such as ISO 11439, ensuring that the products meet the safety and performance requirements for automotive applications.

Example Technical Parameters

Here are some example specifications of CNG-2 composite cylinders:

Product No.	Internal OD (mm)	External OD (mm)	Volume (L)	Length (mm)	Weight (kg)	Wall Thickness (mm)	Working Pressure (MPa)	Material
CNG2-G-325-45-20B	325	334	45	735	36	4.6	20	30CrMo
CNG2-G-325-50-20B	325	334	50	792	40	4.6	20	30CrMo
CNG2-G-325-55-20B	325	334	55	857	42	4.6	20	30CrMo
CNG2-G-325-60-20B	325	334	60	921	46	4.6	20	30CrMo
CNG2-G-325-65-20B	325	334	65	985	50	4.6	20	30CrMo
CNG2-G-325-70-20B	325	334	70	1049	52	4.6	20	30CrMo
CNG2-G-325-75-20B	325	334	75	1113	55	4.6	20	30CrMo
CNG2-G-325-80-20B	325	334	80	1178	59	4.6	20	30CrMo
CNG2-G-325-85-20B	325	334	85	1243	61	4.6	20	30CrMo
CNG2-G-325-90-20B	325	334	90	1306	67	4.6	20	30CrMo
CNG2-G-325-100-20B	325	334	100	1434	71	4.6	20	30CrMo
CNG2-G-325-110-20B	325	334	110	1563	78	4.6	20	30CrMo
CNG2-G-325-120-20B	325	334	120	1691	85	4.6	20	30CrMo

Conclusion

Type 2 CNG composite cylinders (CNG-2) offer a compelling balance of strength, weight, and cost for automotive applications. They are widely used in various vehicle types, providing enhanced performance and safety. Their construction from steel or aluminum liners with hoop-wrapped composite fibers ensures they meet rigorous international standards, making them a reliable choice for storing compressed natural gas in vehicles.