All our BOVs are thoroughly tested to make sure the valve opens and closes properly at the set rates on the springs. The allowable errors for opening and closing of the valves are controlled within 2% more or less. The servicing life of springs and diaphragms used for the BOV lasts for 200, 000 times of operation (open and close) under 200C (or 392F). Materials used for making BOV are high quality aluminum alloy.