莒縣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。在莒縣機械密封系(xi)(xi)(xi)統(tong)(tong)(tong)(tong)中(zhong)，上述系(xi)(xi)(xi)統(tong)(tong)(tong)(tong)并(bing)不同時包括在(zai)內。密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)系(xi)(xi)(xi)統(tong)(tong)(tong)(tong)的(de)選擇主(zhu)(zhu)(zhu)要(yao)取(qu)決(jue)于主(zhu)(zhu)(zhu)密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)件的(de)應用(yong)范圍。例如(ru)，如(ru)果(guo)主(zhu)(zhu)(zhu)密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)用(yong)于高溫(wen)液(ye)體(ti)，密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)系(xi)(xi)(xi)統(tong)(tong)(tong)(tong)應確(que)保(bao)(bao)(bao)降(jiang)(jiang)低主(zhu)(zhu)(zhu)密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)的(de)環境(jing)溫(wen)度(du)，即采(cai)用(yong)溫(wen)度(du)控制系(xi)(xi)(xi)統(tong)(tong)(tong)(tong)。如(ru)果(guo)主(zhu)(zhu)(zhu)密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)用(yong)于固(gu)體(ti)雜(za)質(zhi)含量高的(de)工作介質(zhi)，密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)系(xi)(xi)(xi)統(tong)(tong)(tong)(tong)應確(que)保(bao)(bao)(bao)在(zai)主(zhu)(zhu)(zhu)密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)前降(jiang)(jiang)低固(gu)體(ti)雜(za)質(zhi)含量，即采(cai)用(yong)除(chu)雜(za)系(xi)(xi)(xi)統(tong)(tong)(tong)(tong)。在(zai)腐(fu)蝕(shi)性介質(zhi)中(zhong)，密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)系(xi)(xi)(xi)統(tong)(tong)(tong)(tong)必須確(que)保(bao)(bao)(bao)主(zhu)(zhu)(zhu)密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)降(jiang)(jiang)低腐(fu)蝕(shi)速率(lv)或(huo)消除(chu)腐(fu)蝕(shi)，即使(shi)用(yong)流體(ti)而不是堵塞流體(ti)系(xi)(xi)(xi)統(tong)(tong)(tong)(tong)；在(zai)高壓密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)裝置中(zhong)，輔助系(xi)(xi)(xi)統(tong)(tong)(tong)(tong)應確(que)保(bao)(bao)(bao)多級(ji)降(jiang)(jiang)壓和其他措施，即壓力控制系(xi)(xi)(xi)統(tong)(tong)(tong)(tong)。

　　莒縣機械密封的三(san)個主要功能如下：

　　1、沖洗功能，沖洗是莒縣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。一般的莒縣機械密封應該沖洗，特別是(shi)對于輕烴泵(beng)，沖洗時(shi)達到(dao)隔離介質(zhi)、冷卻和改善潤滑的(de)目的(de)。隔離介質(zhi)的(de)目的(de)可以通過(guo)將與介質(zhi)相容的(de)液體引入密封腔進行外部循環沖洗來實(shi)現。

　　2、除雜和過濾功能，密封流體中的微細固體粒子、污垢等雜質對莒縣機械密封造成的危(wei)害非常(chang)嚴重，可(ke)(ke)能(neng)導(dao)致密(mi)(mi)封端面的磨損，也(ye)可(ke)(ke)能(neng)堵塞寒(han)冷密(mi)(mi)封系統(tong)的管線。密(mi)(mi)封性(xing)系統(tong)軟(ruan)件具有(you)去除殘(can)(can)渣(zha)、保持液體(ti)清潔(jie)的作(zuo)用。當(dang)殘(can)(can)渣(zha)的相對(dui)密(mi)(mi)度小于液體(ti)媒質相對(dui)密(mi)(mi)度時(shi)(shi)，能(neng)用過(guo)濾裝(zhuang)置去除殘(can)(can)渣(zha)；而當(dang)殘(can)(can)渣(zha)的相對(dui)密(mi)(mi)度超過(guo)液體(ti)媒質相對(dui)密(mi)(mi)度時(shi)(shi)，可(ke)(ke)選用旋液分離設備(bei)或(huo)網式過(guo)濾器去除殘(can)(can)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。借助莒縣機械密封可以用雙端莒縣機械密封代替密封(feng)(feng)介(jie)質，將難(nan)以直接密封(feng)(feng)的介(jie)質轉(zhuan)化為(wei)密封(feng)(feng)潤滑(hua)性能好、清潔的密封(feng)(feng)液體(ti)介(jie)質。