This article introduces the function and effect of small noise silencer and the flow adaptation of its valve during steam evacuation in thermal power plant, analyzes the flow-standing pressure characteristics of ZF 416 type noise silencer and the selection of its valve structure. 介绍小孔消声器在电厂蒸汽放空时的消声作用、效果及其阀门流量的适配,分析ZF416型消声器的流量&驻压特性曲线及其阀门结构的选择。