Difference in temperature causes steel to contract or expand. If tubing is free to move, length of the tubing will be either longer or shorter due to thermal expansion. On the other hand, if the tubing is not free to move, there will be a change in axial force due to the temperature effect.
Figure 1 illustrates an increase in length due to heat and Figure 2 demonstrates a decrease in length because of cooling.
Figure 1 – Tubing Lengthen by Temperature Increase
Figure 2 – Tubing Shorten by Temperature Decrease
