This type of gate is designed for temporary shut off of material flow to allow for the removal of the rotary airlock for maintenance. There are primarily two options available when needing this type of valve.  The first option would be the valve shown in the picture which utilizes a hand crank to position the blade into position.  The second option consists of a manually inserted plate into the valve body. When the plate is not in position a bolted cover plate is installed over the blade opening.

Available in carbon steel, stainless steel or aluminum.