CNG Cylinder tanks or CNG Storage tanks typically will take up a portion of the total CNG Cost conversion. It all depends on how many volumes of gas that the owner wants to be installed to the vehicle with consideration such as available cylinder space, weight concerns, budget and desired travel range.
Cylinders are available in a large range of sizes and configurations. It is also possible to install multiple tanks within one vehicle. CNG is stored on board vehicles in high working pressure rated at either 3,000 psi (+200 bar) or 3,600 psi (+250 bar).
There are 4 (four) types of CNG Cylinder available in the market. What differentiates the four types of CNG cylinders is the type of materials used to create the basic structure of the tank, the materials used to line or wrap the inside and outside of the tank, and how they are manufactured.
The type of materials used to create the structure of the tank will determine the weight and cost of the tank. Heavier tanks are typically the least expensive and the lighter tanks are typically more expensive. Each type of cylinder has different reaction to heat and pressure. Each type of cylinders has its own ISO manufacturing standard that has to be followed.
- Type 1 Cylinders
This type of cylinder is made from all metal steel in the shape of a cylinder. These types of tanks are the heaviest tanks on the market. At the same these tanks are the most affordable or cost-effective. Type 1 tanks are typically painted with a protective coating on the outside of the tank.
- Type 2 Cylinders
This type of cylinders is made from metal liner reinforced by composite wrap (glass or carbon fiber) around the middle (hoop wrapped). Liner takes 50% and composite takes 50% of the stress caused by internal pressurization. This is what is called a “hooped wrapped” tank. The composite material wrapper is composed of a woven glass fiber or woven carbon fiber or a combination of both.
Both the metal liner and the composite wrapper each take on about 50% of the internal stress created when the tank is fill with compressed natural gas. Type 2 tanks are much lighter than Type 1 tanks due to the reduction of metal and the use of lighter-weight composite materials. Because of advancements in technology, Type 2 CNG tanks, they are slightly more expensive than Type 1 tanks.
- Type 3 Cylinders
This type of cylinder is made from an aluminum composite material. The aluminum composite material is wrappen completely around the cylinder. This is what is called a “full wrapped” tank. The aluminum composite material wrapped around the metal liner is typcially composed of a woven glass fiber or woven carbon fiber. Type 3 tanks are lighter and stronger than Type 1 and Type 2 tanks, and are more expensive than Type 1 and Type 2 tanks.
- Type 4 Cylinders
Type 4 CNG tanks do not use any metal in their structural design. These types of tanks are made with a “gas-tight” thick rubber membrane. The plastic liner is then reinforced with a composite material using the “full wrapped” method, where the entire tank is wrapped.
The composite wrapper is typically composed of woven glass fiber or a woven carbon fiber material. Almost all of the cylinder’s strength is provided by the composite reinforced wrapper. Type 4 tanks are the lightest CNG tanks on the market. Type 4 tanks are similar in weight and cost the Type 3 tanks.
Whether you required CNG Cylinders for a storage or for your CNG Vehicles, we at PT. Raja Gas Samudra are ready to support. We continuously import CNG Cylinders from several different manufacturers in the world.