RE: Another Trick

Dear Ben,

When the temperature of the outer surface is more than the inner one, then the thermal bowing comes into picture.

I try to explain what I think, I may also be wrong: Take a 12"NB, 1.5D 90 Deg. bend. The outer radius is 619mm, while inner radius is 295mm. The outer surface developed length is 973mm, while the inner surface developed length is 464mm. Now let us take a thermal strain of 0.005mm/mm. The expansion of the outter surface is 4.86mm, whereas that of the inner surface is 2.32mm.
What happens when the bend is subjected with this temperature? Since the outer surface wants to expand more than that of the inner surface, and there is a connecting piping at start and end of bend, then bend bends inward. There is always a end rotation associated with start & end of the bend. At the same time there is ovalization of the bend (flatter from top & bottom surfaces). And this happens at all the temperatures increase. Am I sounding logical?

Regards,
Kaustubh Received on Sat Apr 20 03:14:00 2002