The correct way to Order a Square Elbow:
In fabrication of Square Elbows, there are four pieces: two Cheeks (which will end up being the sides of the elbow), one Throat, and one Heel. In the fabrication process everything starts with the Cheek.
The first dimension of an Elbow is always the Cheek size; the second dimension is the heel. Whether it’s a Vertical Elbow (up and down) or Horizontal Elbow (side to side) will be determined by this dimension sequence.
When a Duct Shop makes a Square Elbow, the sequence of the two dimensions determines how the elbow is made starting from the moment it’s programmed into the Plasma Table’s software.
If the field orders a 12″ x 14″ Square Elbow with turning vanes, the shop is going to make it differently than they would if the field ordered a 14″ x 12″ Square Elbow.
Oddly, a “Cheekbender” has nothing to do with this primary dimension of the Cheek. Instead it is used to turn the 90 degree Right Angle Flange on the Throat and the Heel in a direction that will be inward towards the body of the elbow.
Each of the two Cheeks will then have a Drive turned on the 12″ dimension by means of a Cleatbender.
This 180 degree Open Hem will be facing out from the Cheek, in the same direction as the reinforcement Beads.
