Cylinder main standards
There are several standards for CNG/NGV cylinders today. The mains ones are seems to be ISO, NZ and ANSI.
There are several standards that cover NGV industry regarding the CNG cylinder.
The main international standards are:
-ANSI
-ISO11439
-NZ5454
-ISO4605D
The types of cylinders based on these standards generally fits into one of these types:
CNG1-Metal
CNG2-Metal liner reinforced with resin-impregnated cont inuous filament (hoop-wrapped)
CNG3-Metal liner reinforced with resin-impregnated continuous filament (fully wrapped)
CNG4-Nonmetallic liner with resin-impregnated continuous filament (all-composite).
For same volume of cylinder, CNG1 is generally the heaviest with lowest pricing while CNG4 is the lightest with highest pricing.
There are a few cylinder manufacturers in the world today, fewer yet for CNG2, CNG3 and CNG4.
Currently there is one company in Thailand that is expected to be launching CNG4 cylinders by 3rd quarter of 2008. The name if the company is Plus Lab co., ltd , visit their web site if you would like to find out more information.
Using cylinder in different countries:
For countries which are member of the ISO, generally the use of ISO certified cylinders can be locally manufactured or imported.
However, different countries have different requirement by their local transport department.
For example, in Thailand, accepted standards of cylinders to be used in an automobile are ISO11439,CSA/ANSI NGV-2, UN ECE R110, and
Thailand's local standard TISI2311/ISO11439. For formal registration of the vehicle an official standard certificate from manufacturer matching the serial number on the cylinder must
accompany each and every cylinder (for all cylinders including those manufactured locally).
For more complete list of countries and their accepted standards:
NGV International standards A-K
NGV International standards L-Z