【国外标准】 Standard Specification for Asbestos-Cement Flat Sheet for Cooling Tower Fill (Withdrawn 2019)

This specification covers three classes of flat asbestos-cement sheets for use as cooling tower fill. Specifically excluded from this specification are asbestos-cement products intended for use as: tower partitioning and casing materials, splash bars, water distribution conduits, and demisters; and corrugated sheets and splash bars used as cooling tower fill (heat exchange surfaces). Materials shall be classified into the following types: Type I, fill consisting of autoclaved pressed sheets without textured surfaces; Type II, fill consisting of non-autoclaved pressed sheets without textured surfaces; Type III, fill consisting of non-autoclaved, non-pressed sheets with textured surfaces. Asbestos-cement sheets shall conform to specified manufacturing (autoclave, pressing, texture, and thickness), composition (cement:silica ratio, mineral diluents, cellulose, organic content, and cement type), and performance (apparent density, mater absorption, flexural modulus of rupture, minimum deflection, freeze-thaw resistance, Harkort test, and free lime) requirements.1.1 This specification covers three classes of flat asbestos-cement sheets for use as cooling tower fill.1.2 Specifically excluded from this specification are asbestos-cement products intended for use as tower partitioning and casing materials, splash bars, water distribution conduits, and demisters. Also excluded are corrugated sheets and splash bars used as cooling tower fill (heat exchange surfaces) that are covered in Specification C1081.1.3 The values stated in the SI system are to be regarded as the standard. The inch-pound units in parentheses are provided for information only.1.4 Warning—Breathing of asbestos dust is hazardous. Asbestos and asbestos products present demonstrated health risks for users and for those with whom they come into contact. In addition to other precautions, when working with asbestos-cement products, minimize the dust that results. For information on the safe use of chrysotile asbestos, refer to “Safe Use of Chrysotile: A Manual on Preventive and Control Measures.”21.5 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 appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.