I am spiral duct installer, i've created this app for me, and now I hope that it will be useful for you. Thank you very much.
4 Utilities intended for the professional installer, of galvanised steel spiral rigid duct, especially the one used for ventilation, exhaust extraction, etc...
45 DEGREES PIPES: Calculates the pipe length to 45 degrees, between two parallel lines, knowing the diameter and the distance between centers.
FLUIDS: Calculates the flow (M³/h), knowing the diameter and velocity (m/sec), (obtained speed, using a anemometer).(Metric system only)
EQUIVALENCES: Calculates the equivalent diameter to a rectangular section and vice versa; this being possible, once obtained the diameter, modify the values entered in the rectangle.
HYPOTENUSE: An aid to calculate the distance between centers of two parallel lines. Taking as reference walls, ceilings, etc...The result can be called within 45 DEGREES PIPES app.
Note Version 2 1.0
Some corrections of syntax.