消聲(sheng)(sheng)(sheng)(sheng)器(qi)(qi)（圖4-62）通常(chang)用于介質(zhi)放空(kong)管的終端，以消除可能因高壓高速介質(zhi)的放空(kong)而產生的噪聲(sheng)(sheng)(sheng)(sheng)。通常(chang)包(bao)括蒸汽排(pai)氣消聲(sheng)(sheng)(sheng)(sheng)器(qi)(qi)、氣體排(pai)空(kong)消聲(sheng)(sheng)(sheng)(sheng)器(qi)(qi)、油(you)浴(yu)式消聲(sheng)(sheng)(sheng)(sheng)過(guo)濾器(qi)(qi)、電機消聲(sheng)(sheng)(sheng)(sheng)器(qi)(qi)等(deng)。

  視(shi)鏡（圖4-63）通常用(yong)于冷(leng)卻水(shui)管(guan)道(dao)(dao)和潤滑油管(guan)道(dao)(dao)等，通過其透(tou)明的(de)視(shi)窗可以觀(guan)察(cha)到管(guan)道(dao)(dao)內(nei)循環冷(leng)卻水(shui)或(huo)潤滑油是否在流動。