反壓狀態是不良的工作狀態，介質中的顆粒、雜質很容易進入密封面，使密封失效。磨軸的主要件為橡膠波紋管，且由于上端密封面處于不良潤滑狀態，動靜環之間的摩擦力矩大于橡膠波紋管與軸之間的傳遞轉矩，從而發生相對轉動。動、靜環輔助密封由于受到污水中的弱酸、弱堿的腐蝕，橡膠件已無彈性。渣漿前鋒泵用前鋒機械密封的工作原理要求前鋒機械密封內部無任何雜質，在組裝前鋒機械密封前要徹底清掃動環、靜環、軸套等部件，檢查動靜環表面是否存在劃痕、裂紋等缺陷，這些缺陷存在會造成前鋒機械密封嚴重(zhong)漏泄。必要時可以制(zhi)作工裝(zhuang)在組裝(zhuang)前(qian)水壓試驗(yan)，檢查動靜環座是否存在影響密(mi)封(feng)的缺陷(xian)。

　　渣漿前鋒泵用前鋒機械密封由于密封面變形所引起的，而且前鋒機械密封面泄漏的概率是很高的。如果泵在啟動時就發生前鋒泵用前鋒機械密封泄漏，而拆查密封面時看不見有損壞的地方，這時就應該用平晶檢查前鋒機械密封的(de)變(bian)形情況。如果發生變(bian)形，用平晶檢查(cha)密封面的(de)干涉帶的(de)變(bian)化情況，密封面變(bian)形存在(zai)于動環和靜環之間。

　　壓缸體(ti)動(dong)(dong)(dong)(dong)(dong)態密(mi)(mi)封(feng)(feng)(feng)(feng)系統采(cai)用的(de)是主密(mi)(mi)封(feng)(feng)(feng)(feng)設(she)(she)計(ji)，一(yi)(yi)般都用U型密(mi)(mi)封(feng)(feng)(feng)(feng)圈(quan)。液壓缸體(ti)的(de)往復式動(dong)(dong)(dong)(dong)(dong)態密(mi)(mi)封(feng)(feng)(feng)(feng)系統的(de)設(she)(she)計(ji)，開始使(shi)用了更加復雜的(de)U型圈(quan)和(he)同軸(zhou)(zhou)密(mi)(mi)封(feng)(feng)(feng)(feng)組件的(de)復合(he)式設(she)(she)計(ji)。密(mi)(mi)封(feng)(feng)(feng)(feng)的(de)靜環(huan)(huan)通常固定在(zai)殼體(ti)上(shang)，動(dong)(dong)(dong)(dong)(dong)環(huan)(huan)通過彈簧(huang)(huang)(huang)、彈簧(huang)(huang)(huang)座與(yu)軸(zhou)(zhou)一(yi)(yi)同旋轉(zhuan)。靜環(huan)(huan)與(yu)殼體(ti)、動(dong)(dong)(dong)(dong)(dong)環(huan)(huan)與(yu)軸(zhou)(zhou)形(xing)成的(de)間隙用成型填料(liao)密(mi)(mi)封(feng)(feng)(feng)(feng)。在(zai)動(dong)(dong)(dong)(dong)(dong)環(huan)(huan)和(he)靜環(huan)(huan)接觸的(de)端面形(xing)成相對(dui)滑(hua)動(dong)(dong)(dong)(dong)(dong)面，即動(dong)(dong)(dong)(dong)(dong)密(mi)(mi)封(feng)(feng)(feng)(feng)面。為保證密(mi)(mi)封(feng)(feng)(feng)(feng)良好，動(dong)(dong)(dong)(dong)(dong)密(mi)(mi)封(feng)(feng)(feng)(feng)面應十(shi)分平直(zhi)和(he)光潔。彈簧(huang)(huang)(huang)力和(he)被密(mi)(mi)封(feng)(feng)(feng)(feng)的(de)流體(ti)壓力使(shi)動(dong)(dong)(dong)(dong)(dong)環(huan)(huan)貼(tie)緊(jin)靜環(huan)(huan)。因動(dong)(dong)(dong)(dong)(dong)環(huan)(huan)與(yu)軸(zhou)(zhou)通過彈簧(huang)(huang)(huang)連接，動(dong)(dong)(dong)(dong)(dong)環(huan)(huan)和(he)靜環(huan)(huan)間貼(tie)合(he)性受軸(zhou)(zhou)的(de)振動(dong)(dong)(dong)(dong)(dong)和(he)擺動(dong)(dong)(dong)(dong)(dong)影響(xiang)較(jiao)小。靜環(huan)(huan)一(yi)(yi)般常用潤滑(hua)性好的(de)軟質(zhi)材料(liao)如(ru)石墨、填充(chong)聚四(si)氟乙(yi)烯等(deng)，動(dong)(dong)(dong)(dong)(dong)環(huan)(huan)多用硬質(zhi)合(he)金、陶瓷(ci)等(deng)材料(liao)制造。