Item duplication. 1  Step 1. Have the block you want to duplicate in front of you. ( 2 Examples: Diamond, Gold, or Iron.). 3  Step 2. 4  Now you might want to have a Iron pickaxe or Diamond pickaxe. 5  Step 3. Use you'r pickaxe to quickly mine it.
Heavy Duty/Industrial. A backdraft damper is an isolation damper allowing air in one direction only. Greenheck's HB damper series is designed to prevent back flow at static pressures and velocities up to 20 in. wg and 6400 fpm, respectively.
A backflow preventer is a method or mechanical device to prevent backflow. The basic method of preventing backflow is an air gap, which either eliminates a cross-connection or provides a barrier to backflow. Mechanical backflow preventers are devices that provide a physical barrier to backflow.