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。渣漿泵用長安機械密封的工作原理要求長安機械密封內部無任何雜質，在組裝長安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長安機械密封嚴重(zhong)漏(lou)泄。必(bi)要時可以制作(zuo)工裝在組裝前水壓試(shi)驗，檢查(cha)動靜環座是(shi)否存在影(ying)響密(mi)封的(de)缺(que)陷。

　　渣漿長安泵用長安機械密封由于密封面變形所引起的，而且長安機械密封面泄漏的概率是很高的。如果泵在啟動時就發生長安泵用長安機械密封泄漏，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長安機械密封的(de)(de)變形(xing)情(qing)況(kuang)(kuang)。如果發生變形(xing)，用平晶檢(jian)查密封面(mian)的(de)(de)干(gan)涉帶的(de)(de)變化情(qing)況(kuang)(kuang)，密封面(mian)變形(xing)存在于動環和(he)靜(jing)環之間。

　　壓缸(gang)體(ti)動(dong)(dong)(dong)(dong)態密(mi)(mi)(mi)封(feng)(feng)(feng)系(xi)統(tong)采(cai)用(yong)的是主密(mi)(mi)(mi)封(feng)(feng)(feng)設(she)(she)計，一般都用(yong)U型(xing)密(mi)(mi)(mi)封(feng)(feng)(feng)圈(quan)。液壓缸(gang)體(ti)的往復(fu)式動(dong)(dong)(dong)(dong)態密(mi)(mi)(mi)封(feng)(feng)(feng)系(xi)統(tong)的設(she)(she)計，開始使用(yong)了更加復(fu)雜的U型(xing)圈(quan)和同(tong)軸(zhou)(zhou)密(mi)(mi)(mi)封(feng)(feng)(feng)組件的復(fu)合式設(she)(she)計。密(mi)(mi)(mi)封(feng)(feng)(feng)的靜(jing)(jing)環(huan)(huan)(huan)(huan)(huan)通(tong)常固定在殼體(ti)上，動(dong)(dong)(dong)(dong)環(huan)(huan)(huan)(huan)(huan)通(tong)過彈簧(huang)(huang)(huang)、彈簧(huang)(huang)(huang)座與(yu)(yu)(yu)軸(zhou)(zhou)一同(tong)旋轉。靜(jing)(jing)環(huan)(huan)(huan)(huan)(huan)與(yu)(yu)(yu)殼體(ti)、動(dong)(dong)(dong)(dong)環(huan)(huan)(huan)(huan)(huan)與(yu)(yu)(yu)軸(zhou)(zhou)形成(cheng)的間隙用(yong)成(cheng)型(xing)填料(liao)密(mi)(mi)(mi)封(feng)(feng)(feng)。在動(dong)(dong)(dong)(dong)環(huan)(huan)(huan)(huan)(huan)和靜(jing)(jing)環(huan)(huan)(huan)(huan)(huan)接(jie)觸的端面形成(cheng)相對滑(hua)動(dong)(dong)(dong)(dong)面，即(ji)動(dong)(dong)(dong)(dong)密(mi)(mi)(mi)封(feng)(feng)(feng)面。為保證(zheng)密(mi)(mi)(mi)封(feng)(feng)(feng)良好(hao)，動(dong)(dong)(dong)(dong)密(mi)(mi)(mi)封(feng)(feng)(feng)面應(ying)十分平直和光(guang)潔。彈簧(huang)(huang)(huang)力(li)和被密(mi)(mi)(mi)封(feng)(feng)(feng)的流體(ti)壓力(li)使動(dong)(dong)(dong)(dong)環(huan)(huan)(huan)(huan)(huan)貼緊靜(jing)(jing)環(huan)(huan)(huan)(huan)(huan)。因動(dong)(dong)(dong)(dong)環(huan)(huan)(huan)(huan)(huan)與(yu)(yu)(yu)軸(zhou)(zhou)通(tong)過彈簧(huang)(huang)(huang)連(lian)接(jie)，動(dong)(dong)(dong)(dong)環(huan)(huan)(huan)(huan)(huan)和靜(jing)(jing)環(huan)(huan)(huan)(huan)(huan)間貼合性受軸(zhou)(zhou)的振動(dong)(dong)(dong)(dong)和擺動(dong)(dong)(dong)(dong)影響較(jiao)小。靜(jing)(jing)環(huan)(huan)(huan)(huan)(huan)一般常用(yong)潤(run)滑(hua)性好(hao)的軟質材料(liao)如石墨(mo)、填充(chong)聚(ju)四氟乙烯等(deng)，動(dong)(dong)(dong)(dong)環(huan)(huan)(huan)(huan)(huan)多用(yong)硬質合金、陶瓷等(deng)材料(liao)制造。