Cannot wrap my head around

[JennyFlow]

There are a million threads on this but for some reason I can't understand exactly how the carbon doser is different from a quality dual stage regulator and I need people to yes/no/sorta my comments to help me understand

With a carbondoser, the solenoid valve is used instead of a needle valve to control the (size? / frequency? / or is this totally wrong?) of the co2 bubble right?

A dual stage regulator has only one knob correct, this knob lets more co2 through but even if it were wide open, if the the needle valve were nearly closed only a small amount of co2 gets through right? The only reason to have a valve on the regulator is so the needle valve does not need to resist such pressure right?

Thanks!

 

[mcgyvr]

The "CarbonDoser" uses a "low cost" dual stage regulator to help make it more reliable..

A good quality dual stage regulator does not require the additional solenoid valve to provide the same reliability.