Hi,
Fuel oil piping system to burners of fired heaters, include supply and return lines.
I have some questions about return lines.
what is the purpose of return lines? I have read that those are for continuous circulation of an amount of fuel oil in fuel system. is that all?
Another issue (the main) is the control philosophy for the return line. It is said that back pressure regulator to be installed on return line. why?
How is the flow rate of return line controlled?
And finally the location of return line branch. is it before supply control valve or after?
thank for sharing your valuable information.