消(xiao)聲(sheng)(sheng)(sheng)器（圖4-62）通常(chang)用(yong)于介(jie)質(zhi)放(fang)空(kong)管的終(zhong)端(duan)，以消(xiao)除可能因高壓(ya)高速介(jie)質(zhi)的放(fang)空(kong)而產生的噪聲(sheng)(sheng)(sheng)。通常(chang)包括(kuo)蒸汽排氣消(xiao)聲(sheng)(sheng)(sheng)器、氣體排空(kong)消(xiao)聲(sheng)(sheng)(sheng)器、油(you)浴(yu)式消(xiao)聲(sheng)(sheng)(sheng)過濾器、電機(ji)消(xiao)聲(sheng)(sheng)(sheng)器等(deng)。

  視鏡（圖4-63）通(tong)常用于冷卻水管(guan)道和潤滑(hua)油管(guan)道等(deng)，通(tong)過(guo)其透明的視窗可(ke)以觀(guan)察到管(guan)道內循環冷卻水或潤滑(hua)油是否在流(liu)動。