Calculated Industries 4090 - Manual (Page 105)

104 — ITI S
HEET
M
ETAL
/HVAC P
RO
With Offset = “y” and Length = “x,”
WrapperLength (aka StretchOut) = CenterlineRadius * ArcK * 4θ
HeelRadius = CenterlineRadius + (a ÷ 2)
ThroatRadius = CenterlineRadius – (a ÷ 2)
CenterlineRadius = =
SlantLength
4Sin(θ)
SlantLength 2
4 * Offset
θ = ArcSin = ArcTan
Offset
SlantLength
( )
= ArcTan
Offset
Length
( ) y
x ( )
APPENDIX C — OFFSET FORMULAS