The regulator is a pressure release valve, its operated by one bolt at the end of it, tighten it (clockwise) will increase the vacuum pressure in the system, turn it counterclockwise will decrease the system vacuum pressure. You should do the adjustment with a pressure indicator like a vacuum gauge in the same system. If the valve get stuck at the frame, you can release it from the connection end, by pushing a screw driver or a small stick into it to release it. Remember, the best pressure range is 10 to 12 inch Hg for all milkers.
