The thermal screens in widest use today are (1) thermal cycling, (2) steady
high temperature, and (3) thermal shock. The thermal cycling screen is
recognized by the IES as being the most cost effective although the other two
are used in some special situations.
The thermal screens described by the two methods herein, thermal survey and
heritage, should be considered only as starting profiles. The effectiveness of
any screen should be evaluated by engineering analysis of the equipment and
the expected flaws, using factory and field failure data, and the failure
history of the equipment during and subsequent to the screen, adjusting the
screen parameters as the screen matures.