Linear Thermal Expansion of Pipping;

One factor that must be considered in the design of the piping system is Piping Flexibility. Because our pipes will stretch itself when the temperature is increased, and shrink when the temperature is dropped. Therefore, our piping system must be flexible or able to move back and forth sufficiently to support elongation or shrinkage of pipe.

In ASME B31.3 Process Piping Design determines the Linear Thermal Expansion of each material. To be used to calculate how much piping will stretch or shrink according to how much temperature has changed. The values ​​in Table C-2 measure from 20°C (“zero” values). The values ​​are Minus will mean the pipe will shrink, and or a Positive value means that the pipe will be elongated.

Therefore, when examining Piping, make sure to check the Support area to see if it is in the right condition. This is so that Pipping can expand and contract when there is temperature change without interruption or constraint.

Linear Thermal Expansion of Pipping – Example; 

Let’s take a look at an example of the Linear Thermal Expansion pipe request from Table C-2 in ASME B31.3, Look at the Factor “B” – Linear expansion per 1 meter, which is divided by the material of the pipe.

Let us look at the required temperature (Design- temperature), for example at a temperature of 200*C, the Carbon Steel (CS) pipe will stretch 2.3 mm per pipe length 1 m and the Stainless Steel (SS) pipe will stretch 3.1 mm per pipe length 1 m from the temperature at 20*C

In this example, we find that the pipe SS will stretch over the pipe CS, so the connection (Joining) Dissimilar Materials (eg CS with SS), Thermal Expansion is one factor to consider carefully. When we put the equipment or pipeline applications where high temperatures can create High-Stress area of welding joint with dissimilar welding.