P1 burner question

[jtz54]

I have a backyard oven with a P1 burner. I had some trouble recently and found the gas regulator had gone bad so I replaced it. The oven lights and fires up fine but I noticed a hissing sound coming from a port just ahead of the gas shutoff valve (see picture). Is this normal and what is this port for?

[UtahBeehiver]

My guess is that it is a relief check valve. You will need to get someone with a CGI or TIF (these are combustible gas indicators). Most HVAC pros will have this equipment. This needs to be rectified before you start up your oven, don't be cheap on this. I worked in the natural gas industry and know what can happen with leaking gas in an enclosed area.