BREATHER VALVES Sizes / End Connections DN 2" to 12" according to model. Standard flanged connection, ANSI 150 lbs. Other types of connection on request Calibration Min./max.: 2.2 to 50 mBar according to model (adjustment by means of weighted plug) Pressures > 50 mBar on request (spring-loaded safety valve) Materials BODY/DISC/SEAT: Aluminium, cast iron, carbon steel, stainless steel MEMBRANE: Teflon, Viton (other materials on request) Principle Breather valves limit emissions of volatile or noxious substances from storage tanks. The valves only open when necessary at a pre-set pressure or vacuum calibration value. Can be used in conjunction with a flame arrestor for inflammable subtances. Suitable for a wide range of petroleum products and chemicals. Description Calculation of suction and discharge rates and sizing of breather valves according to API 2000