Abstract: An apparatus is adapted to be secured to a pressure regulator, relief valve, or any other valve and allows the user to control the position of the valve. According to one embodiment, the pressure regulator remains fully open until a desired maximum fill pressure within a boiler is reached. Upon reaching the maximum fill pressure, the valve is automatically and substantially instantly closed. Consequently, the pressure within the boiler never exceeds the maximum allowable pressure of the pressure relief valve, thereby preventing the accidental discharge of hot, high-pressure water from the boiler. Moreover, because the valve remains fully open until the maximum fill pressure is achieved, the amount of time to fill the boiler is substantially reduced. According to another embodiment, a relief valve remains fully closed until a maximum pressure is exceeded, whereby the valve is substantially instantly fully opened.