gas systems

I am trying to see if anyone on this forum knows about Gas diversity systems. This was a way for gas companies, here in my state of Ct. it would be Yankee gas, to determine gas loads. I have spoke to Yankee gas, but the person I talked to didn't have a clue, I think he was pretty young or not around long enough. I am trying to help a client with this "diversity". From what I can gather, its a system that even though lets say the full load for a specific user is 200,000 btus with all appliances in use, but we all know that more times than non, that all applainces are not all on at the same time. I know at my home, which is gas, I do not use in the winter months my gas bbq grill and gas stove at the same time. Of in the summer months my gas fireplace and gas furnace, no need for the furnace to run in the summer. I have a seperate gas hot water heater. Can anyone shed more information about this please. I really need to get some hard information about this subject.

Don't really know what you are looking for but many times in design diversity is taken into account for lots of systems, electrical comes to mind right off of the bat. When we design an electrical layout we also do a load calc that lets us reduce certain loads (commercial buildings).

All you are really trying to do is set a minimum size for the piping. Just calculate the most likely scenario of which appliances will be on at the same time and then compute the pipe sizes needed for that. Then good luck getting it approved by the inspection department, since they use the standard tables which assume MAXIMUM usage.