Abstract: A port closure and method of installing the same. The port closure includes, in combination, a tank, a closure member and an actuator. The tank has defining walls, an exterior surface, an interior surface, an interior cavity and an access port. The closure member is disposed within the interior cavity of the tank. The closure member has an access port engaging face that is larger than a cross-sectional area of the access port. The actuator is coupled with the closure member and moves the closure member between a first position in which the access port engaging face closes the access port and a second position laterally spaced from the access port.