前言:本出版物代表了农业动物隔离建筑用直接燃气循环加热器的安全操作、坚固耐用的结构和可接受性能的基本标准。这是多年来在为农业动物圈养建筑设计的直接燃气循环加热器的制造、测试、安装、维护、检查和研究方面经验的结晶，该加热器用于天然气的利用。某些设备存在对人员造成伤害的风险，如果完全消除，将破坏设备的效用。本标准中的规定旨在减少此类风险，同时保持设备的正常功能。本标准中的任何内容均不得以任何方式被视为表明质量指标超出了其包含的规定。 其设计允许农业动物隔离建筑使用直接燃气循环加热器，其结构和性能可能超过本文规定的各项规定。在准备过程中，充分认识到通过巧妙设计进行改进的可能性。随着进展，可能需要进行修订。如果认为这些建议是可取的，则应将其转发给国际批准服务公司——美国公司，地址:俄亥俄州克利夫兰东普莱森特山谷路8501号，邮编:44131。本文件后面提供了一份提案表。农业动物隔离建筑用直接燃气循环加热器的安全和满意运行在很大程度上取决于其正确安装，并且应按照国家燃气规范ANSI Z223进行安装。 1、制造商安装说明和当地市政建筑规范。范围:1.1.1本标准适用于新生产的40万Btu（117 228 W）或以下的直接燃气循环加热器（见第四部分，定义），以下简称加热器，完全由新的、未使用的零件和材料制成，主要用于农业动物隔离建筑中的永久安装。加热器产生的所有燃烧产物都被释放到被加热的区域。这些要求适用于设备进气口处供气压力额定值不超过1/2 psi（3.45 kPa）的加热器。1.1.2本标准不适用于温室内使用的加热器。1.1.3本标准适用于带有整体空气循环装置的独立加热器。 1.1.4本标准不包括采用无焰催化燃烧工艺的加热器、与液相燃料气体一起使用的加热器或红外型加热器。1.1.5本标准适用于空气出口温度高于或低于室温350°F（176.5°C）的加热器（见2.8.2）。1.1.6适用于室外安装加热器的特殊结构规定见1.2.5、1.3.5、1.3.6、1.5、1.7.3、1.9.3-2b和1.22.4.1.1.7本标准涵盖的加热器适用于天然气或液化石油气。与上述气体一起使用的加热器的构造在第一部分中进行了说明。与上述气体一起使用的加热器的性能在第二部分中进行了说明。1.1.8适用于喷水冲洗装置的加热器的特殊结构规定见下文1。 2.7和1.21.1.1.1.9附件A包含本标准中具体引用的标准列表，以及这些参考标准的来源。1.1.10如果本标准中给出的测量值后跟其他单位的等效值，则第一个规定值应视为规范值。1.1.11除非另有规定，否则本标准中提及的所有psi均应视为表压。

Preface:This publication represents a basic standard for safe operation, substantial and durable construction, and acceptable performance of direct gas-fired circulating heaters for agricultural animal confinement buildings. It is the result of years of experience in the manufacture, testing, installation, maintenance, inspection and research on direct gas-fired circulating heaters for agricultural animal confinement buildings designed for the utilization of gas. There are risks of injury to persons inherent in some appliances that, if completely eliminated, would defeat the utility of the appliance. The provisions in this Standard are intended to reduce such risks while retaining the normal function of the appliance.Nothing in this standard is to be considered in any way as indicating a measure of quality beyond compliance with the provisions it contains. It is designed to allow compliance of direct gas-fired circulating heaters for agricultural animal confinement buildings, the construction and performance of which may exceed the various provisions specified herein. In its preparation, full recognition has been given to possibilities of improvement through ingenuity of design. As progress takes place, revisions may become necessary. When they are believed desirable, recommendations should be forwarded to International Approval Services - U.S., Inc., 8501 East Pleasant Valley Road, Cleveland, Ohio 44131. A proposal form is provided in the back of this document.Safe and satisfactory operation of direct gas-fired circulating heaters for agricultural animal confinement buildings depends to a great extent upon its proper installation, and it should be installed in accordance with theNational Fuel Gas Code, ANSI Z223.1, manufacturers' installation instructions, and local municipal building codes.Scope:1.1.1This standard applies to newly-produced direct gas-fired circulating heaters (see Part IV, Definitions) of 400,000 Btu (117 228 W) or less, hereinafter referred to as heaters, constructed entirely of new, unused parts and materials and primarily intended for permanent installation in agricultural animal confinement buildings. All the products of combustion generated by the heater are released into the area being heated.These requirements apply to heaters having a gas supply pressure rating not exceeding 1/2 psi (3.45 kPa) at the gas inlet of the appliance.1.1.2This standard does not apply to heaters intended for use in greenhouses.1.1.3This standard applies to self-contained heaters with integral means for air circulation.1.1.4This standard does not cover heaters employing a flameless catalytic combustion process, heaters for use with liquid phase fuel gases or infrared type heaters.1.1.5This standard applies to heaters having an air outlet temperature of 350°F (176.5°C) above room temperature or less (see 2.8.2).1.1.6Special construction provisions applicable to a heater for outdoor installation are outlined under 1.2.5, 1.3.5, 1.3.6, 1.5, 1.7.3, 1.9.3-2b and 1.22.4.1.1.7Heaters covered by this standard are intended for use with natural or liquefied petroleum gases.The construction of heaters for use with the above-mentioned gases is covered under Part I.The performance of heaters for use with the above-mentioned gases is covered under Part II.1.1.8Special construction provisions for heaters intended for installations subject to spray washdown are outlined under 1.2.7 and 1.21.1.1.1.9Exhibit A contains a list of standards specifically referenced in this standard, and sources from which these reference standards may be obtained.1.1.10If a value for measurement as given in this standard is followed by an equivalent value in other units, the first stated value is to be regarded as the specification.1.1.11All references to psi throughout this standard are to be considered gage pressure unless otherwise specified.