I am ready to install the last leg of gas line that will supply a 30" free standing gas range. The supply to this leg so far is 3/4" black iron. It seems to me that, given what's readily available, the most efficient valve and flex connection line combo are both 1/2". Since I have not yet found a 3/4" to 1/2" gas valve I have the option of using a 3/4" to 1/2" 90* elbow in the final upward (through the floor into the kitchen behind the stove) supply leg making the final connections easy and with minimal adaptors or joints. My question is this: Would there be any issues in doing the reduction to a 1/2" supply in this final section? The flow through should remain adequate for the needs of the stove? Or is it better to keep everything 3/4" right through the valve and use reducers to make the final 1/2" connections. Just looking for a few pros/cons, or what the norm is before I finish.

Thanks to all.

Herb

I would run 3/4" up to the stove. Good luck, Tom

You can buy a 3/4 inch flex line, it may not have the right fittings on the end that you need so tell the clerk that you need a fitting that is 3/4 inch flare but will screw into a 3/4 inch iron pipe fitting.
Or you could use a 7/8 flex line and it will have the 3/4 inch iron pipe fittings on it. Make sure that if you are screwing it into something you need a male end, if you are screwing something into it you need a female end. I hope this helps.

I do not think you will have a problem going to a 1/2 inch now you shouldn't need that much gas unless your using all burners and oven at the same time even then you wouldn't notice.

If you use a smaller flex line than you need and you have the oven and perhaps one of the burners you will hear a whistling noise, it will be the gas whistling through the flex connector. If you don't believe me when you go to buy one pick up one of the 3/8 inch ones and blow through it.