本标准描述了½英寸。（13毫米）至6英寸。（150 mm）排气阀和½英寸。（13毫米）至20英寸。（500 mm）空气/真空阀和组合空气阀，具有灰铸铁、球墨铸铁、碳钢板或不锈钢阀体和盖。这些阀门设计用于最大设计压力为300 psig（2070 kPa[表压]）的水或废水系统，液体温度范围从高于冰点到最高125°F（52°C），液体pH值大于6小于12。本版C512的主要修订内容包括: 1.对标题和范围进行了修改，以包括废水处理用空气阀的注意事项和要求。2.在适当的情况下，减少了与饮用水接触的材料的铅要求。3.范围修改为包括钢板和不锈钢阀体和要求。4.增加了各种水域的定义。5.增加了废水应用中空气阀的压力测试要求。6.增加了废水应用中空气阀的清洗孔。7.修改了内部和外部涂层部分，以包括水和废水应用中空气阀的涂层要求和测试。 8.增加了焊接和制造要求。

This standard describes ½-in. (13-mm) through 6-in. (150-mm) air-release valves and ½-in. (13-mm) through 20-in. (500-mm) air/vacuum valves and combination air valves having gray cast-iron, ductile-iron, carbon steel plate, or stainless-steel bodies and covers. The valves are designed for use in water or wastewater systems with maximum design pressures of 300 psig (2,070 kPa [gauge]), liquid temperatures ranging from above freezing to a maximum of 125°F (52°C) and a liquid pH greater than 6 and less than 12.Major revision to this edition of C512 include the following:1. Title and scope were modified to include considerations and requirements for air valves for wastewater service.2. Reduced lead requirements for materials in contact with potable water were included where appropriate.3. Scope was modified to include steel plate and stainless-steel bodies and requirements.4. Definitions of various waters were added.5. Pressure testing requirements for air valves in wastewater applications were added.6. Cleanouts for air valves in wastewater applications were added.7. Internal and External Coating sections were modified to include coating requirements and testing for air valves in water and wastewater applications.8. Welding and fabrication requirements were added.