Festo. In process automation applications,the pressure and flow of gases are tightly controlled. Inert gas systems, for example, are used to prevent the atmosphere in reactors and process tanks in a plant from coming into the explosive range. Other applications include the transfer of materials between process tanks and filling, frequently found in the food and drinks industry. To control these functions, dedicated lines with regulating valves and flow meters are generally used. With proportional-valve technology, plant managers can control and adjust the pressure and flow levels of inert gasses more accurately to achieve the optimum for the process. By integrating the proportional valves on an intelligent valve terminal, diagnostic capabilities can be extended. In addition, proportional valves mounted in this way have a smaller space requirement meaning they can be installed inside control cabinets positioned in a non-ATEX zone; the explosion protection requirements can be reduced thereby further reducing installation costs.