Bar is specific volumetric unit of air pressure - kilogram is weight volume unit of any mass which can be contained in a vessel
what WE see on CNG station pressure meters (BAR in red) in black it is 200- 230 PSI
14.503 PSI (pounds per sq in) = 1 BAR - - 1 bar <= 0.98 kilograms
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when such high pressure is released in cylinder it starts to store when capacity is topped up the pressure sensor in dispenser cut-off the pressure stops the discharge and meter comes to halt.