Do you know what CNG tank trailers are? Do you know how they’re used and their different aspects? If not, here are some answers. A Compressed Natural Gas tanker is the full name of a CNG tank trailer. The trailer is used to move high-pressure, compressed natural gas in cylinders to other locations, usually sub-stations for CNG. A trailer is necessary to move CNG from the main fueling station to a sub-station, because many CNG locations don’t have underground tubes.
There are four types of CNG trailers, and the manufacturing process is different for each one. For example, the type one model is easier to process than type four. It is also important to mention that the cylinders used to transport CNG should be unibody or integrated. Therefore, as in the case with other types of heavy-duty trailers, there is no welding in this manufacturing process.
When shopping for a CNG tank trailer, it’s important to know the twelve processing steps, so you can buy a trailer that meets all safety standards. You never want a substandard or unsafe trailer. Before purchasing a CNG tanker, be sure of what you’re buying. Get structural and mechanical drawings to understand the construction.
The processing steps are: Inspect steel tubes; hot shell nosing; bottle neck cutting; rough machining; quenching, heat treatment, and tempering; polishing the outside; hydrostatic testing; steam drying; inner shot peening; inspecting the inner tube; airtight and non-destructive testing; and paint spraying and assembly.
CNG Tubes Trailer Definition
As mentioned earlier, a CNG trailer is used in the transportation of compressed natural gas and has different designs and may carry a variety of seamless steel cylinders. A CNG tanker is also fitted with a pressure gauge, a thermometer, and a safety device. In the setup, a gas tube and valve are used to connect every cylinder.
The structures of the CNG trailer have a frame type and a bundling type. The bundling type usually consists of (among other accessories) seamless steel cylinder, a framework, and a pipeline operating system.
The cylinders are fixed on a trailer of the bundling type; however, the quality of the framework can be reduced on this type of structure. On the other hand, this type has a larger volume, lower costs, and higher efficiency.
Different Kinds of CNG Tubes
There are four kinds of CNG tubes for trailers. These include: CNG-1, CNG-2, CNG-3, and CNG-4. With each higher number, the tubes have more filament, are lighter in weight, are more difficult to manufacture, and more expensive.
CNG-1 is made of aluminum alloy or steel and are the heaviest tubes. They are the most cost-effective and the exterior of the tube has a protective coating. CNG-2 gas cylinders are filament wound composite with the interior made of aluminum or steel.
Long fibers impregnated with resin are wrapped around the heads. In general, CNG-2 tubes are more expensive and lighter than CNG-1. A CNG-3 cylinder is referred to as a full wrapped or fully wrapped tank. The inner part is made of aluminum or steel and the body and head of the tube is wrapped with long, resin-impregnated fibers made of carbon or glass.
If you’re looking for the lightest cylinder, purchase CNG-4. This one has inner parts made of plastic and the tube’s body and head is wrapped using long fibers with resin. CNG-4 is also the most expensive.
Before You Buy
Prior to making any purchase of a CNG tank trailer, every buyer should understand how the trailer is manufactured, and consider the reputation of the seller. Be sure you have the correct product and that it will fit your needs.