Blast gate capable of preventing gate-dropping

A blast gate capable of preventing gate-dropping, the blast gate comprising:

• a base comprising
• a main body;
• a flow channel formed in the main body;
• at least one positioning hole formed on the main body;
• and
• a gate channel formed in the main body and communicating with the flow channel and the at least one positioning hole;
• and
• a gate inserted in the gate channel of the base, configured to move back and forth in the gate channel to open or close the flow channel, and comprising
• a board;
• at least one positioning tab protruding from the board along a first direction, being elastic, and being engageable in the at least one positioning hole along the first direction;
• and
• at least one compensation rib protruding from the board along a second direction being opposite to the first direction;
• wherein when the at least one positioning tab is engaged in the at least one positioning hole, the at least one compensation rib abuts an inner wall around the gate channel so as to push the at least one positioning tab toward the at least one positioning hole.