ABSTRACT

Insulative Coatings have been used for over 20 years for personnel protection and energy retention. However, the industry still lacks certain test methods that can validate the thermal performance of these coatings. There are standards to determine the coating’s thermal conductivity, but none to determine watt usage and thermal efficiency at different conditions. Watt usage and thermal efficiency can be determined with thermal modeling programs. But, comparisons of predictions from thermal programs and field data sometimes do not agree. As a result, a new lab test method was developed to determine watt usage and thermal conductivity at various conditions. The objective was to determine if lab data do indeed agree with predictions in thermal modeling programs and to ASTM tests that determine thermal conductivity. If there is close agreement, then this might validate the use of this test as another tool in the lab to determine thermal performance of insulative coatings. This report describes the development of this test, gives details of the test set-up and compares test data to a thermal modeling program and to an ASTM test that measures thermal conductivity.

INTRODUCTION

Thermal Insulative coatings (TICs) have been used for over 20 years and they have a good history. A TIC is typically made with an acrylic waterborne resin system containing proprietary fillers that have very low thermal transmission properties (thermal conductance). They are typically spray applied or sometimes troweled on hot or ambient industrial piping and equipment in multiple coats. A TIC is differentiated from standard insulation materials which are typically greater in thickness and applied as solid or fibrous blocks or forms to the equipment/piping. TICs allow for application to many different geometrical shapes without the need for special fabrication as the coating conforms to any surface. A corrosion protective primer, such as epoxies or epoxy phenolic/novolacs, is often applied to the steel surface prior to application of the TIC.

Their initial and still primary benefit is to provide personnel protection against burns to the skin in the event of an accidental contact with a hot pipe or vessel. Other benefits have also been realized such as reflective barrier properties, anti-condensation on cold equipment, maintaining process stability during rapid weather changes and energy retention. Since they are bonded to a primed metal substrate, there is no air gap between the insulative coating and the metallic substrate that water could penetrate. Insulation materials that have this air gap, have the disadvantage that water can enter the gap and degrade the corrosion protective coating which can lead to corrosion of the steel substrate at a much faster rate. Therefore, the TIC can significantly reduce or eliminate the possibility of corrosion under insulation.

This content is only available via PDF.
You can access this article if you purchase or spend a download.