Compression Copper Gas fittings / pipes

[Rich Sumen]

I have never seen this.
The entire house from the exterior gas meter, into the home has these
compression fittings with copper gas supply pipes. All were labeled "Natural Gas" on the interior runs. This appears to be standard copper piping.
It some cases, the copper pipe connects to some small pieces of standard gas pipe fittings, just before going to the appliances.
Is this allowed? Code? The house is 4 years old, located in Ohio.
Pics attached.
Any comments, Code referances?

Thanks / Rich

[Dom D'Agostino]

They're Pro-Press fittings. They are marked for gas, and use an o-ring and crimping tool.

[Rod Butler]

This is actually a very decent product and even though a bit spendy produces a very clean final installation. Some installers love it for the labor savings.

[Zibby Bujno]

picture #3. If its drip leg then it should be 3" min.
As far as Propress copper for natural gas line, hummm...

[Binford Tools]

http://www.nachi.org/forum/attachments/f20/7320d1164742380-surface-yellow-gas-flex-piping-csst-gas-pipe.jpgwith the price of copper, or the issue with thief, I would think its a dying form of piping. I see a lot of the yellow flex stuff now.