... , oil mill, cement factory, silo system or other factory. PFB Series Pneumatic Flap BoxPrinciple A plate is flapped wiggly by pneumatic ... switch pneumatic cylinder, acting quickly, working stably, and operating easily. Japanese SMC or German Festo cylinder and solenoid valve is optional ... , oil mill, cement factory, silo system or other factory PFB Series Professional High Quality Pneumatic Flap Box