The new line of pressure relief doors prevents ductwork from imploding or exploding in the event of excess pressure. The PZ10 (positive) and the VT10 (negative) pressure relief doors are designed to open automatically 1-inch w.g. above normal operating system pressure. The pressure relief doors have a field-adjustable nonmechanical latch.

A.J. Manufacturing Inc., 1217 Oak St., Bloomer, WI 54724; 800-328-9448;

Publication date: 12/19/2005