TOPIC: pressure relief valve and Gas Line

Gas Line was connect to pressure relief valve. (see Photo)
Anyone help me how do I comment.

As with your other thread, we need more info, more pics, broader view of the entire system, your thoughts, on what you see, and why you suspect something is wrong.

The gas line in was through the pressure relief valve and connect to the heater and use heating source.
I'm 1st time saw that. It can be possible?

Very difficult to see in your pic, but it looks like a Watts valve (gas cutoff), not a pressure relief valve. Need a better pic to tell for sure. Did the WH have a TPR Valve installed?? If not, then it's is/should be a Watts valve. Also, that gas line could have been installed a whole lot better.

I thought it was a Watts valve. The connection can be used for pressure discharge pipe?
Thank you !

I see your post on the Nachi site, and have responded there also.

I guess I need to know what your definition of a "pressure discharge pipe" is??

The fuel line should be running from the main fuel supply, through the Watts valve, and then terminates at the WH control valve. There is no "discharge".

The Watts (cutoff) valve is typically installed where a TPR Valve is not practical for the installation. Where is the WH located at? Above a finished space??