This is my outdoor faucet. There is some kind of a pressure relief valve at the bottom of the facet. Every time the water is shut off in the house some water leaks from the this valve. I can remove the valve by turning the nut above the valve but then the water simply streams out. There is an anti-Siphon Vacuum Breaker also attached to the faucet. The leaks are directly where we sit outdoors and makes us jump when the vale opens and leaks water. Help.
This looks like a "frost free hose bib", they are interrupting water flow inside your house insulation envelope. When you close it, remaining water is draining through that valve so only empty pipe is left out in the cold.
There are different versions without such a valve, but those can freeze if you forget to detach the hose.