[yamshe]

Hello
can anyone tell me about the control of gas systems in the boiler

[eugenedakin]

Hello yamshe,

There are many types and configurations of boilers.

Here is an articles where different configurations are explained:
http://en.wikipedia.org/wiki/Boiler

Are you looking for the gas (fuel) portion of control, or are you looking for the pressurized gas control thermally created from a boiler?

Thanks for your clarification,

Eugene