When the municipal water supply network stops , the pressure of inlet disappears , first , second level check valves close , at the same time , because the conduit do not supply pressure to the lower cavity of diaphragm of drainage device , the valve flap of the drainage device opens under the force of spring , as well as the pressure between the first , second level check valves , to discharge off the backflow medium between the two check valves , so as to play the role of anti - pollution and isolation , even if the second level check valve occurs leakage , the backflow medium will also be discharged outside , and will not flow into the main network 当市政管网停水,进口压力消失,一、二级止回阀关闭,同时由于导管不再向排污器膜片下腔供给压力,排污器的阀瓣在弹簧力和一、二级止回阀间介质压力作用下而打开,把两止回阀间回流的介质排放掉,这样起到防污隔断作用,即使第二级止回阀出现内漏,回流的介质也会经排污器排到外面,而不会流进主管网。
The study instructs simulating valve leakage experiment , perfects valves leakage test technology and bases theoretically for applying valve leakage test in practice . the test stand is constructed and instrumented to accept a variety of valves in order to determine which characteristics of acoustic emission change with leakage rate . the data for each valve type is generated by varying valve type and working medium 建立模拟在用承压阀门内漏实验台,研究典型阀门内漏声源的声学特性,确定声发射特征参量与泄漏率的关系,为定量评价阀门泄漏率提供实验数据;通过对不同类型、不同规格、不同工作介质下的典型承压阀门内漏的实验研究,确定阀门内漏最佳检测区域,建立在用承压阀门内漏声学检测方法。
Currently , china ' s production of a common valve leakage , which leak , visual quality is not high , short life , and not flexible operating valves and electrical devices such as pneumatic devices unreliable shortcomings of some products , only the equivalent of the early 1980s , the international standard 目前我国企业生产的各种阀门普遍存在着外漏、内漏、外观质量不高、寿命短、操作不灵活以及阀门电动装置和气动装置不可靠等缺点,部分产品只相当于上世纪80年代初的国际水平。