Calculated Industries 4090 - Manual (Page 53)

52 — ITI S
HEET
M
ETAL
/HVAC P
RO
(Cont’d)
KEYSTROKE DISPLAY
4. Calculate Centerline Radius, Wrapper Length, Heel Radius,
Throat Radius and Theta:
Ç ( RAD 77-7/16
INCH
( WL 84-5/8
INCH
( HEEL 111-7/16
INCH
( THRT 43-7/16
INCH
( THET 15.6571°
5. Convert Theta to degrees:minutes:seconds:*
Ç • DMS 15.39.26
6. Multiply by two to double offset:**
x 2 = DMS 31.18.51
*The angle of Theta can be used to divide the offset into degreed elbows for more
manageable sections. If the angle calculated is used, there would be four (4) elbows
each at 15°39’26”.
**If two (2) elbows were desired, the calculated angle can be doubled (each elbow
would be 31°18’51”). Doubling Theta provides the maximum elbow size for this offset
and radius combination. The total angle on either side of center can be divided into as
many elbows as is required to make the offset manageable. In the case above, the
maximum angle that can be divided is 31°18’51”.