- Author
- Kusuda, T. | Ellis, W. M.
- Title
- Boiling Tests of Non-Asbestos-Based Thermal Insulation Used in Air-Conduit Underground Heat Distribution Systems.
- Coporate
- National Bureau of Standards, Washington, DC
- Sponsor
- Naval Facilities Engineering Command, Washington, DC Directorate of Civil Engineering, Washington, DC Office of Chief of Engineers, Washington, DC
- Report
- NBSIR 81-2324, September 1981, 114 p.
- Distribution
- Available from National Technical Information Service
- Keywords
- boiling test | conduit system | pipes | thermal insulation | underground heat distribution systems
- Abstract
- Non-asbestos-based thermal insulation around steam carrier pipes is commonly used in conduit underground heat distribution systems for many of the Tri-service installations. When the conduit fails, the insulation is expected to undergo severe boiling action due to the possible ingress of underground water. If the insulation is properly fabricated, it should withstand the prolonged boiling such that its thermal performance would be restored when the ground water is drained and the system dried. Several selected insulation systems were boiled in an open tank as well as in the conduit to test their ability for retaining the original insulation capability. Although most of the calcium silicate-based insulation systems fell off the carrier pipe under the open tank boiling within 72 hours, they were able to withstand 96 hours of continuous boiling in the conduit. When drained and dried, these systems restored their thermal insulation performance to within 10 percent of the original value.