Heat transfer fluids are used in a broad spectrum of process systems. They
provide protection against freezing, corrosion, and fouling of the system a
nd have low vaporization losses at high operating temperatures. Recent expe
rience shows the value of chemical cleaning and system monitoring of therma
l fluid systems to prevent corrosion and failure of system components, to i
mprove heat transfer efficiency and operating margin, and to eliminate toxi
c materials from fluids and internal surfaces.