An apparatus for actuating a valve includes an actuator with a cap. A plate that engages the inner diameter of the actuator housing is positioned within the actuator housing. A pressure chamber is located within the actuator housing between the plate and cap. A cap seal fluidly seals the pressure chamber between the cap and the actuator housing. The pressure chamber is fluidly sealed at the plate by one of a first plate seal assembly and a second plate seal assembly. The first plate seal assembly is formed by the diaphragm being secured between a seal nut and the plate. The second plate seal assembly is formed by an outer diameter sidewall seal located between the inner diameter of the actuator housing and the outer diameter of the plate and a retainer seal located between an outer diameter of the seal nut and an inner diameter of the plate.