A Pittsburgh lock provides an airtight seam on medium and low pressure duct-work without the need to lay out and hand bend each part of the lock. Lockformer Pittsburgh machines use a series of rolls to fold metal into the form of a Pittsburgh. An improperly adjusted Lockformer will cause the metal to split from excessive pressure or form a loose seam that does not create an airtight seal. Regularly adjusting the roll tension of the machine will ensure that a rolled Pittsburgh seam will provide the correct amount of tension to seal the duct seam.
Disconnect the power from the Lockformer machine.
Match a socket from a socket set to the size of the bolts holding the cover on the top of the Pittsburgh Lockformer machine. Secure the socket to the 1/2-inch drive ratchet handle. Turn each bolt counterclockwise with the ratchet handle. Set the bolts aside. Lift the cover from the Lockformer.
Exchange the socket on the ratchet handle for one that fits the hold-down bolts located on the top center section of the rolls. Turn both bolts clockwise until tight. Reverse the direction of the ratchet. Turn each bolt 3/4 turn counterclockwise.
Set the cover onto the Lockformer. Thread each cover bolt into the machine. Tighten the bolts to secure the cover to the machine.
Plug in the power to the Lockformer.