RVP-R-EX Volume Flow Controllers are suitable for constant and variable flow applications. RVP-R-EX Volume Flow Controllers can be used in the both fresh air and exhaust air ventilation systems. RVP-R-EX Volume Flow Controllers are used in the potentially explosive atmosphere in which gases, vapors, mists and air-dust mixtures are found in order to provide high safety level. They are designed and certified in order to meet the requirements of the ATEX 94/9/EC directive. They are classified as group II category 2 explosion proof devices that can be used in the explosion hazard zones 1,2,21 and 22. The ATEX Certificate is valid for the electrical components.