The AL air locks and BL blow through valves have been designed for many applications in the metering and pneumatic conveying of products in powder and granular form. The product line also includes USDA approved models for sanitary use in the food and pharmaceutical industry. The AL and BL valves are available in 10 consecutive sizes from 100-500, covering a capacity range of the rotor from 0.8-230 liter per revolution at 100 % filling.