上安鄉機械密封包括壓力控制、溫度控制、流體替換(堵塞)和雜質去除系統。在上安鄉機械密封系(xi)(xi)統(tong)(tong)(tong)(tong)(tong)中(zhong)，上述系(xi)(xi)統(tong)(tong)(tong)(tong)(tong)并不同時包括在(zai)(zai)內。密(mi)封(feng)(feng)(feng)(feng)系(xi)(xi)統(tong)(tong)(tong)(tong)(tong)的(de)選擇主(zhu)要取決(jue)于主(zhu)密(mi)封(feng)(feng)(feng)(feng)件的(de)應用(yong)(yong)范圍。例如，如果主(zhu)密(mi)封(feng)(feng)(feng)(feng)用(yong)(yong)于高(gao)溫(wen)液體，密(mi)封(feng)(feng)(feng)(feng)系(xi)(xi)統(tong)(tong)(tong)(tong)(tong)應確(que)保降低主(zhu)密(mi)封(feng)(feng)(feng)(feng)的(de)環(huan)境溫(wen)度，即采用(yong)(yong)溫(wen)度控制系(xi)(xi)統(tong)(tong)(tong)(tong)(tong)。如果主(zhu)密(mi)封(feng)(feng)(feng)(feng)用(yong)(yong)于固體雜(za)質(zhi)含(han)量(liang)高(gao)的(de)工作介質(zhi)，密(mi)封(feng)(feng)(feng)(feng)系(xi)(xi)統(tong)(tong)(tong)(tong)(tong)應確(que)保在(zai)(zai)主(zhu)密(mi)封(feng)(feng)(feng)(feng)前(qian)降低固體雜(za)質(zhi)含(han)量(liang)，即采用(yong)(yong)除雜(za)系(xi)(xi)統(tong)(tong)(tong)(tong)(tong)。在(zai)(zai)腐蝕性介質(zhi)中(zhong)，密(mi)封(feng)(feng)(feng)(feng)系(xi)(xi)統(tong)(tong)(tong)(tong)(tong)必須確(que)保主(zhu)密(mi)封(feng)(feng)(feng)(feng)降低腐蝕速率或消除腐蝕，即使(shi)用(yong)(yong)流體而不是堵塞流體系(xi)(xi)統(tong)(tong)(tong)(tong)(tong)；在(zai)(zai)高(gao)壓密(mi)封(feng)(feng)(feng)(feng)裝(zhuang)置中(zhong)，輔助系(xi)(xi)統(tong)(tong)(tong)(tong)(tong)應確(que)保多級降壓和(he)其他措施，即壓力控制系(xi)(xi)統(tong)(tong)(tong)(tong)(tong)。

　　上安鄉機械密封的三個主要功能如(ru)下：

　　1、沖洗功能，沖洗是上安鄉機械密封基本的功能，它直接將液體注入單面密封或雙面密封的高壓側。一般的上安鄉機械密封應該(gai)沖洗(xi)，特(te)別(bie)是(shi)對于輕烴(jing)泵，沖洗(xi)時達(da)到(dao)隔離(li)介(jie)質(zhi)、冷卻和(he)改善潤滑的(de)目的(de)。隔離(li)介(jie)質(zhi)的(de)目的(de)可以通過(guo)將與(yu)介(jie)質(zhi)相容的(de)液體(ti)引入密封腔(qiang)進行外部循環(huan)沖洗(xi)來實現(xian)。

　　2、除雜和過濾功能，密封流體中的微細固體粒子、污垢等雜質對上安鄉機械密封造(zao)成的(de)危害非(fei)常嚴重，可(ke)(ke)能(neng)(neng)導致密(mi)(mi)封(feng)(feng)端(duan)面的(de)磨損(sun)，也可(ke)(ke)能(neng)(neng)堵塞寒冷密(mi)(mi)封(feng)(feng)系(xi)統的(de)管(guan)線。密(mi)(mi)封(feng)(feng)性(xing)系(xi)統軟件具有去(qu)除殘渣(zha)、保(bao)持(chi)液體(ti)清(qing)潔的(de)作用(yong)(yong)。當(dang)(dang)殘渣(zha)的(de)相對密(mi)(mi)度小于(yu)液體(ti)媒(mei)質(zhi)相對密(mi)(mi)度時，能(neng)(neng)用(yong)(yong)過濾(lv)裝(zhuang)置去(qu)除殘渣(zha)；而當(dang)(dang)殘渣(zha)的(de)相對密(mi)(mi)度超過液體(ti)媒(mei)質(zhi)相對密(mi)(mi)度時，可(ke)(ke)選用(yong)(yong)旋液分離設(she)備或網式過濾(lv)器去(qu)除殘渣(zha)。

　　3、流體替代功能，含有固體顆粒的氣相介質和液相介質的直接密封難度很大，它們溫、毒、貴、易蒸發、易結晶。借助上安鄉機械密封可以用雙端上安鄉機械密封代替密封介質(zhi)，將難以直接密封的介質(zhi)轉(zhuan)化(hua)為密封潤滑性(xing)能好、清潔(jie)的密封液體介質(zhi)。