A pressure regulator for use in an elbow connector for use with a sprinkler assembly including a pressure responsive member, movably mounted in the elbow connector and movable from an open position allowing flow of water into the sprinkler assembly and a closed position where the bottom edge of the pressure responsive member blocks the flow of water into the sprinkler assembly. The pressure responsive member is biased in the open position and moves into the closed position when downstream water pressure exceeds a predetermined value.