ASTM C411-2019 pdf free download

ASTM C411-2019 pdf free download.Standard Test Method for Hot-Surface Performance of High-Temperature Thermal Insulation
1. Scope
1.1 This test method covers the determination of the perfor- mance of commercial sizes of both block and pipe forms of thermal insulating materials when exposed to simulated hot- surface application conditions. The term “hot-surface perfor- mance” has reference to a simulated use-temperature test in which the heated testing surface is in a horizontal position. 1.2 This test method refers primarily to high-temperature insulations that are applicable to hot-side temperatures in excess of 150°F (66°C). It is used for materials such as preformed insulations, insulating cements, blankets, and the like, by proper laboratory preparation of the samples. 1.3 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appro- priate safety, health, and environmental practices and deter- mine the applicability ofregulatory limitations prior to use. 1.5 This international standard was developed in accor- dance with internationally recognized principles on standard- ization established in the Decision on Principles for the Development of International Standards, Guides and Recom- mendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
4. Significance and Use
4.1 Performance in service is the final measure of value for a thermal insulation, but simulative service tests give useful indications. One type involves application for a specified time to a surface heated at a temperature approximately that of intended service, and noting during the test and afterward, changes in the material and its properties. Measurement of these changes are used for predicting what occurs in service as a result of exposure to temperatures corresponding to those of the tests.
5. Apparatus
5.1 Heating Plate—The heating plate shall consist of a corrosion-resistant and heat-resistant plate with a preferred exposed test area of 36 by 18 in. (914 by 457 mm), but having a minimum test area of 18 by 18 in. (457 by 457 mm). The heated area shall have an insulated, heated guard area having a minimum width of3 in. (76 mm) around the entire periphery of the test area. The plate shall be supported in a horizontal plane at a sufficient number of points to prevent sagging. It shall be heated on the under side by gas or electricity. The surface temperature of the plate shall be measured by not less than five thermocouples. Four of the thermocouples shall be located along the diagonals that extend from the corners ofthe exposed area of the plate and at a distance of 6 in. (152 mm) in from each corner. A fifth thermocouple shall be located near the center of the test plate area. The temperature at no point of measurement shall vary more than 65 % or 625°F (614°C), whichever is less, from the desired temperature. A heating chamber beneath the heating plate shall be formed to retain the heat generated by the heating means. A 6-in. thickness of insulation shall form the bottom and the sides, and the heating plate shall form the top of the chamber. Two suitable types of heating plates are shown in Fig. 1 and Fig. 2. 5.2 Heating Pipe—The heating pipe shall consist of a corrosion-resistant and heat-resistant pipe having a length of not less than 3 ft (0.9 m) and preferably 6 ft 6 in. (1.98 m). It shall be supported horizontally. The nominal diameter of the pipe shall preferably be 3 in. (76 mm). The pipe shall be heated electrically with a spiral heating coil placed along the inside of the pipe. Supplementary end heaters, and a guard section at least 3 in. long of the same insulation as that being placed on the test section, shall also be provided to guard against excessive losses from the ends of the test specimen. (Where possible, the use of standard thermal conductivity pipe test apparatus to serve as the heating pipe is recommended.) The surface temperature of the pipe shall be measured by means of thermocouples, not less than one for each 1 ft (0.3 m) oflength ofthe test specimen, and located spirally around the pipe at 90° intervals.