興城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。在興城機械密封系(xi)(xi)(xi)(xi)統(tong)(tong)(tong)(tong)中(zhong)，上(shang)述系(xi)(xi)(xi)(xi)統(tong)(tong)(tong)(tong)并不同時包括在內。密(mi)(mi)封(feng)(feng)系(xi)(xi)(xi)(xi)統(tong)(tong)(tong)(tong)的選擇主(zhu)要取決于(yu)主(zhu)密(mi)(mi)封(feng)(feng)件的應(ying)用(yong)范圍。例(li)如，如果(guo)主(zhu)密(mi)(mi)封(feng)(feng)用(yong)于(yu)高(gao)溫(wen)液體(ti)(ti)(ti)，密(mi)(mi)封(feng)(feng)系(xi)(xi)(xi)(xi)統(tong)(tong)(tong)(tong)應(ying)確(que)保降低主(zhu)密(mi)(mi)封(feng)(feng)的環(huan)境溫(wen)度，即(ji)(ji)采用(yong)溫(wen)度控制(zhi)系(xi)(xi)(xi)(xi)統(tong)(tong)(tong)(tong)。如果(guo)主(zhu)密(mi)(mi)封(feng)(feng)用(yong)于(yu)固(gu)體(ti)(ti)(ti)雜(za)質(zhi)含量高(gao)的工作介質(zhi)，密(mi)(mi)封(feng)(feng)系(xi)(xi)(xi)(xi)統(tong)(tong)(tong)(tong)應(ying)確(que)保在主(zhu)密(mi)(mi)封(feng)(feng)前(qian)降低固(gu)體(ti)(ti)(ti)雜(za)質(zhi)含量，即(ji)(ji)采用(yong)除雜(za)系(xi)(xi)(xi)(xi)統(tong)(tong)(tong)(tong)。在腐蝕性(xing)介質(zhi)中(zhong)，密(mi)(mi)封(feng)(feng)系(xi)(xi)(xi)(xi)統(tong)(tong)(tong)(tong)必須確(que)保主(zhu)密(mi)(mi)封(feng)(feng)降低腐蝕速率或消除腐蝕，即(ji)(ji)使(shi)用(yong)流(liu)體(ti)(ti)(ti)而不是堵塞流(liu)體(ti)(ti)(ti)系(xi)(xi)(xi)(xi)統(tong)(tong)(tong)(tong)；在高(gao)壓(ya)密(mi)(mi)封(feng)(feng)裝置(zhi)中(zhong)，輔(fu)助系(xi)(xi)(xi)(xi)統(tong)(tong)(tong)(tong)應(ying)確(que)保多(duo)級降壓(ya)和其他措施，即(ji)(ji)壓(ya)力控制(zhi)系(xi)(xi)(xi)(xi)統(tong)(tong)(tong)(tong)。

　　興城機械密封的三個主要功能如(ru)下：

　　1、沖洗功能，沖洗是興城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。一般的興城機械密封應該(gai)沖(chong)洗，特別是對于輕烴(jing)泵，沖(chong)洗時達到(dao)隔離(li)(li)介(jie)質(zhi)、冷(leng)卻和改善潤滑的(de)目(mu)的(de)。隔離(li)(li)介(jie)質(zhi)的(de)目(mu)的(de)可以通過將與介(jie)質(zhi)相容(rong)的(de)液體引入(ru)密封腔進(jin)行外部循環沖(chong)洗來實現(xian)。

　　2、除雜和過濾功能，密封流體中的微細固體粒子、污垢等雜質對興城機械密封造(zao)成的危害非常嚴重(zhong)，可能(neng)導致密(mi)封端面(mian)的磨損，也(ye)可能(neng)堵(du)塞寒冷密(mi)封系統的管線。密(mi)封性系統軟件具有(you)去(qu)除殘(can)渣(zha)、保(bao)持液(ye)體(ti)清潔(jie)的作(zuo)用(yong)。當(dang)殘(can)渣(zha)的相(xiang)(xiang)對(dui)密(mi)度(du)(du)小于(yu)液(ye)體(ti)媒(mei)質(zhi)相(xiang)(xiang)對(dui)密(mi)度(du)(du)時，能(neng)用(yong)過濾裝置去(qu)除殘(can)渣(zha)；而(er)當(dang)殘(can)渣(zha)的相(xiang)(xiang)對(dui)密(mi)度(du)(du)超過液(ye)體(ti)媒(mei)質(zhi)相(xiang)(xiang)對(dui)密(mi)度(du)(du)時，可選用(yong)旋(xuan)液(ye)分離設備或網(wang)式(shi)過濾器(qi)去(qu)除殘(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。借助興城機械密封可以用雙端興城機械密封代替密(mi)封(feng)介(jie)質，將難(nan)以(yi)直接密(mi)封(feng)的介(jie)質轉化為密(mi)封(feng)潤滑性能好(hao)、清(qing)潔(jie)的密(mi)封(feng)液(ye)體介(jie)質。