1. A pneumatically actuated field device of a processing plant having a pressurized air source and a pneumatic positioning drive, the pneumatically actuated field device comprising:an electropneumatic solenoid valve including:
an air supply channel configured to connect to the pressurized air source, an air dispensing channel configured to connect to the pneumatic position drive, and an air exhaust channel, wherein the air supply channel, the air dispensing air channel, and the air exhaust channel communicate with an air chamber;
a flapper valve member including a closure element arranged in an axial control direction, the closure element being formed of ceramics and as a circular ball, wherein the closure element is engageable with a mouth of a delimitation interior wall of one of the air supply channel and the air exhaust channel such that the flapper valve member is arranged with a circumferential axial distance, with respect to the axial control direction, to the delimitation interior wall;
an electromagnetic controller configured to displace the flapper valve member in the axial control direction to ventilate or exhaust the air dispensing channel; and
a spring configured to bias the flapper valve member into a closed position to close the one of the air supply channel and the air exhaust channel, wherein the flapper valve member is float-mounted in an unguided configuration within the air chamber,
wherein the flapper valve member further includes a magnetizable flapper plate having at least one closure side to be arranged facing at least one of the air supply channel and the air exhaust channel to be closed or to be released, and being engageable with an axial contact wall of the air chamber to be magnetized by the electromagnetic controller of the solenoid valve, in which at least one the air supply channel and an air exhaust channel is formed, and at each closing position of the magnetizable flapper plate, the magnetizable flapper plate maintains a circumferential axial distance to the delimitation interior wall, wherein: the at least one closure side is at least surface-sectionally formed with a non-magnetizable cover material including a Teflon layer, or the magnetizable flapper plate is a non-metallic material provided with metallic particles having magnetic properties.