Flexible gas tubing should not be bent like this.
This is an unprofessional installation.
Or, perhaps, through the years, it has been bent over and over in different ways as the range has been moved out and then back in.
All of these twists and turns put stress onto the gas line.
This is a flexible gas tubing.
It is vulnerable to damage, splitting, and crimping can cause a lesser flow of gas to the appliance.
Just because it is flexible does not mean you can do this to it.
Everything has its tolerances.
Gastite is a manufacturer of flexible gas tubing, which they call Corrugated Stainless Steel Tubing, or more commonly CSST.
Of course Gastite has a website. All CSST manufacturers have websites!
Each website has its installation instructions.
Each manufacturer wants to make sure its product is not vulnerable to stress, damage, or ignorant installation.
Each manufacturer has a chart like this one, which I found on the Gastite website.
As to the bend radius of various diameters of tubing they all agree.
Everything has its tolerances. And you DON'T want to stress gas tubing! A gas leak behind a kitchen range is simply NOT the way to go!
My recommendation: have a peek behind a kitchen range! Gas or electric, the installation behind must be done properly. And an anti-tip device is a recent, but important, criterion as a part of the installation so the unit cannot fall forward. But don't mess with gas lines! Of all things, don't mess with gas lines!
Jay Markanich Real Estate Inspections, LLC
Based in Bristow, serving all of Northern Virginia.
Office (703) 330-6388 Cell (703) 585-7560