Thermal Expansion Load in Piping System

Thermal expansion load is the load incurred as a result of thermal expansion in piping system. Thermal expansion load can be divided as follow:
-          Thermal expansion load which is caused movement is restricted by support during expansion.
-          Thermal expansion load because of high difference of temperature and working very fast in the wall pipe so it can impact to stress on the wall pipe.
-          Thermal expansion load because different coefficient of expansion between different material.

Support of pipes is installed along piping system to withstand both occasional load and sustain load. However if the increase of temperature in the piping system occur during operation, the pipe will experience expansion so produce high stress either in the fitting are or rigid support area. In this case, location and type of support must be well designed to get optimum analysis stress during operation. The use of loop for expansion is an alternative solution to overcome the large thermal expansion.

Analysis of thermal load calculation on the support can use guide cantilever method in which pipe is modeled as a beam which is held rigidly at one of edge and at some point it is given support, so the amount of stress can be calculated on that support. Force and moment that occur due to thermal expansion load can be seen the equation below:

P = 12 E I Δ / L3
M = 6 E I Δ / L2
Where:
P          = Force at support (N)
M         = Moment at support (N/m)
E          = Modulus elasticity (Pa)
I           = Moment area inertia (m4)
Δ          = Additional length because thermal expansion (m)
L          = Length of pipe (m)