序言这是CSA 2.17《高空燃气设备》的第四版。它取代了1991年出版的前一版。范围1。1本标准涵盖了燃气器具的结构和性能*（见第3条，定义），其输入功率不超过40万Btu/h（117.23 kW）†以确定其是否适合在高空使用。这些设备包括熔炉、锅炉、房间加热器、单元加热器、热水器，以及现场条件表明有必要进行高空使用测试的其他设备（见第3条定义）。测试速率是指在600英尺（152米）或29.38英寸汞柱（99.2千帕）压力的基准下设备的输入。*根据制造商的选择，第5条“性能”中规定的试验可在较高的温度下进行- 海拔位置。†该输入限制反映了高海拔地区检验机构目前的要求（即低于40万Btu/h（117.23 kW）的设备必须符合本标准的要求）。输入超过40万Btu/h（117.23 kW）的电器仍可能被审查是否符合本标准。1.2本标准适用于在2000至4500英尺（610至1370米）或0至4500英尺（0至1370米）高度范围内使用的第1.1条中规定的设备。1.3在本标准中，“应”用于表示要求，即用户为遵守本标准而有义务满足的规定；“应该”用于表示建议或建议但不需要的建议；“可”用于表示一个选项或在标准范围内允许的选项。 注释随附条款不包括要求或替代要求；随附条款的注释的目的是将解释性或信息性材料与文本分开。表和图的注释被视为表或图的一部分，可以作为要求编写。附件被指定为规范性（强制性）或信息性（非强制性）来定义其应用。

PrefaceThis is the fourth edition of CSA 2.17, Gas-fired appliances for use at high altitudes. It supersedes the previous edition published in 1991.Scope1.1 This Standard covers the construction and performance* (see Clause 3, Definitions) of gas-fired appliances with inputs up to and including 400 000 Btu/h (117.23 kW)† to determine their suitability for use at high altitude. The appliances include furnaces, boilers, room heaters, unit heaters, water heaters, and such other appliances where field conditions indicate the necessity of testing for high altitude use (see Clause 3, Definitions). The test rate means the appliance's input at a datum of 600 ft (152 m) or 29.38 in Hg (99.2 kPa) pressure. * At the option of the manufacturer, tests specified in Clause 5, Performance, may be conducted at a high-altitude location. † This input limitation reflects what is currently required by inspection authorities in high-altitude areas (i.e., appliances under 400 000 Btu/h (117.23 kW) must meet the requirements of this Standard). Appliances with inputs in excess of 400 000 Btu/h (117.23 kW) may still be reviewed for compliance with this Standard. 1.2 This Standard applies to appliances specified in Clause 1.1 when for use over an altitude range of 2000 to 4500 ft (610 to 1370 m), or 0 to 4500 ft (0 to 1370 m). 1.3 In this Standard, "shall" is used to express a requirement, i.e., a provision that the user is obliged to satisfy in order to comply with the standard; "should" is used to express a recommendation or that which is advised but not required; and "may" is used to express an option or that which is permissible within the limits of the Standard. Notes accompanying clauses do not include requirements or alternative requirements; the purpose of a note accompanying a clause is to separate from the text explanatory or informative material. Notes to tables and figures are considered part of the table or figure and may be written as requirements. Annexes are designated normative (mandatory) or informative (nonmandatory) to define their application.