Many pumps I see have a spigot attached to the pressure side of the pump plumbing; usually immediately after the pipe leaves the pump outlet. I assume this is for pressure relief but now that I am at that point in my plumbing I can't afford assumptions. Most filters have a pressure valve; why not just use that? Putting male brass (metal) threads into a female pvc adapter is considered one of the weakest plumbing connections one can make (or so I have read).
Can anyone verify what that spigot is there for? Has anyone experienced any failures with similar plumbing?