Primary/secondary on single zone gravity conversion

I am in the process of improving the way I pipe boilers, this is something I do every year as I gain more knowledge about hydronics. My reason for wanting to do this type of piping is strictly for boiler protection, I have a few sketches but don't kown how to post them so for those of you that can and is a lot more knowledgable than I am if you could please post any recommendations I will be grateful. Thanks.