本文件规定了应用领域、尺寸、物理化学、设计和 D系列A型直列式防真空阀的液压、机械和声学特性。 本文件涵盖了D系列A型直列式防真空阀，旨在防止空气污染 饮用水回流，仅由反虹吸引起。 适用于公称通径DN 10至DN 50的直列式防真空阀。购买本文件时可获得的所有当前修订均包含在购买本文件中。

This document specifies the field of application, the dimensional, the physico-chemical, the design, the hydraulic, the mechanical, and the acoustic characteristics of in-line anti vacuum valve family D Type A. This document covers in-line anti vacuum valve family D Type A, intended to prevent pollution of potable water by backflow, caused by backsiphoning only. It is applicable to in-line anti vacuum valve in denominations DN 10 up to DN 50.All current amendments available at time of purchase are included with the purchase of this document.