What is this valve called. -78 safari

[bacevedo]

When connect to public water, I have a constant leak out of the fresh water exterior drain tube. If I block the tube at the outlet, the water will start to pool up on top of this valve where the label is (see image).

I already have a pressure regulator before the water get to this valve. I am guessing that this valve is to relieve excess pressure in the fresh water line. I think the valve is allowing water to trickle out even though the pressure is not that high.

I believe this is an internal pressure release valve but after an hour of Googling, I cannot find a replacement part. Does anyone one know what it is called or where I can get a replacement part?


This is a 78 sarafi with pex plumbing.