A variety of pipe thermal insulation materials has been characterized for thermal properties using the ASTM C 335 Horizontal Pipe Apparatus. The materials represent commercially available pipe insulation that were received and tested between January 1981 through December 1997. These insulation materials are typically used in buildings and industrial manufacturing facilities.
For many materials, there are sufficient replicates to establish a range in the thermal conductivity of the material and an estimate of the material variability. The apparatus used in these measurements was included in a round robin interlaboratory evaluation. The results of that evaluation were published in a previous paper.
Since all commercially available pipe insulation materials experience variation in physical properties such as density, wall thickness, installation methods, etc. there is a corresponding variation in the thermal properties. By evaluating each material over a long time period, the variation in thermal performance can be estimated. This information can be used to determine the proper thermal conductivity for best and worst case scenarios.
Tables and plots of the measured apparent thermal conductivity of various pipe insulation materials is presented showing the range and statistical variability of each materials. All the data has been calculated according to the methods described in ASTM C 335-95 “Standard Test Method of Steady-State Heat Transfer Properties of Horizontal Pipe Insulation” and C 1045-97 “Standard Practice for Calculating Thermal Transmission Properties Under Steady-State Conditions”