Monitoring of ultra-high purity product storage tanks during transportation

System for the transportation and storage of a product which comprises a tank including cylindrical wall section and two ends, wherein the cylindrical wall section and two ends define a cylindrical tank periphery, and wherein the tank periphery has an interior and an exterior. The system utilizes a valve box that includes one or more side walls, a bottom wall, and a removable, sealable top cover which can be attached to the one or more side walls to seal the valve box, wherein the valve box side walls are sealably joined to the cylindrical wall. One or more process valves are disposed in the valve box, wherein each valve has a first and a second end, wherein each first end is connected to a pipe which passes through a wall of the valve box for introducing product into the tank or withdrawing product from the tank. A purge valve and pressure measurement means are installed in fluid communication with the valve box. The product in the tank is isolated from the atmosphere surrounding the tank when the valve box is sealed.