Thermal expansion 1

[AravindSujay]

Hi Guys,

In my current project for Indirect heaters, I would like to calculate the Thermal expansion of the tubes of size 30" OD with the design temperature of 300 Deg F which runs for 52' in length. I took the linear co-efficient of expansion as 8.30E-05 for carbon steel pipes and was able to calculate the expansion in length wise. But I need the expansion in Diameter wise. That is how much will a 30"OD expand?

Need all your expertise in this.
Thanks in advance,
Aravind Sujay

 

[desertfox]

Hi AravindSujay

Just treat the 30" o.d. as you did the length

30*8.05*10^-5*temp diff

regards

desertfox

 

[25362]

It appears that the thermal linear expansion coefficient for steel is in error. It should be 8.3[×]10^-6/^oF. Kindly confirm.

 

[desertfox]

Hi 25362

Yes it should be 10^-6 I agree.
When I look the value up it says 6.3* 10^-5 however I wonder what the value is at 300F as the figure I have here is at room temp.

regards

desertfox

 

[25362]

To desertfox:

[•] The figure quoted by you at ambient temperature is too high by a factor of 10.
[•] The figure I quoted suits the range in question.
[•] I found the following link which may be useful:

http://www.engineeringtoolbox.com/thermal-expansion-pipes-d_283.html

 

[MJCronin]

Aravind,

Are you trying to calculate expansion of this heater for a stress analysis of piping that is attached ?

-MJC

 

[25362]

Perry (6th Ed.) gives for steel's linear thermal expansion, the following equation:

L_t = L_o (1 + [α]t + [β]t²)​

L_t is the length at t in ^oC
L_o is the length at 0^oC
[α] = 0.1118[×]10^-4
[β] = 0.0053[×]10^-6

The equation is applicable over the temperature range 0^oC[→]750^oC.

 

[AravindSujay]

Hi all, I used 30*8.05*10^-6*temp diff.
Thanks for all your answers.