壓(ya)(ya)力(li)(li)容(rong)器(qi)法蘭(lan)是(shi)(shi)(shi)壓(ya)(ya)力(li)(li)容(rong)器(qi)的(de)常用(yong)(yong)部件，是(shi)(shi)(shi)連(lian)接各種(zhong)壓(ya)(ya)力(li)(li)容(rong)器(qi)部件的(de)基本元件，廣(guang)泛地(di)用(yong)(yong)于石(shi)油、石(shi)化(hua)、電力(li)(li)、原子能、輕工(gong)等領域。對于容(rong)器(qi)而(er)言，應該是(shi)(shi)(shi)一(yi)個組(zu)件，包括法蘭(lan)、墊(dian)片(pian)和連(lian)接螺栓或(huo)螺柱以及(ji)螺母，其作用(yong)(yong)是(shi)(shi)(shi)使不同(tong)(tong)的(de)受壓(ya)(ya)元件組(zu)合在一(yi)起，同(tong)(tong)時保證(zheng)連(lian)接部位不發生泄(xie)漏(lou)。法蘭(lan)連(lian)接的(de)主要失效形式(shi)為(wei)接頭的(de)剛度失效，其外部表現型式(shi)為(wei)泄(xie)漏(lou)。壓(ya)(ya)力(li)(li)容(rong)器(qi)內部的(de)介質具有高溫、高壓(ya)(ya)的(de)特(te)點，同(tong)(tong)時具有易燃、易爆的(de)特(te)性(xing)(xing)或(huo)毒性(xing)(xing)，一(yi)旦產生泄(xie)漏(lou)，將(jiang)發生嚴重的(de)次生災(zai)害，嚴重威脅壓(ya)(ya)力(li)(li)容(rong)器(qi)本體和周圍設備以及(ji)人員(yuan)的(de)安全。因(yin)(yin)此容(rong)器(qi)法蘭(lan)的(de)設計和選用(yong)(yong)應優(you)先考慮(lv)的(de)因(yin)(yin)素是(shi)(shi)(shi)整體密封(feng)性(xing)(xing)能。

  我(wo)國(guo)壓(ya)(ya)(ya)力容器(qi)法(fa)(fa)蘭(lan)標(biao)準(zhun)(zhun)自成體系。最早的(de)壓(ya)(ya)(ya)力容器(qi)法(fa)(fa)蘭(lan)標(biao)準(zhun)(zhun)可(ke)以追溯到20世(shi)紀(ji)70年代，當時(shi)使用(yong)的(de)是由原一機部、石油部、化工(gong)部三(san)部共同發布的(de)壓(ya)(ya)(ya)力容器(qi)法(fa)(fa)蘭(lan)行業標(biao)準(zhun)(zhun)JB 1157~1164-1973.經過長期的(de)試(shi)用(yong)及不(bu)斷的(de)修訂，目(mu)前最新的(de)標(biao)準(zhun)(zhun)為NB/T 47020~47027-2012《壓(ya)(ya)(ya)力容器(qi)法(fa)(fa)蘭(lan)》。

  就法(fa)(fa)蘭(lan)(lan)的結構型式和(he)工作原理而言(yan)，壓(ya)力容(rong)器(qi)法(fa)(fa)蘭(lan)(lan)和(he)管法(fa)(fa)蘭(lan)(lan)沒有(you)多大差(cha)異。比較(jiao)明(ming)顯(xian)的區別是，壓(ya)力容(rong)器(qi)法(fa)(fa)蘭(lan)(lan)規格較(jiao)大，與各(ge)類壓(ya)力容(rong)器(qi)連(lian)(lian)接(jie)使(shi)用；而管法(fa)(fa)蘭(lan)(lan)常常與管子(zi)直接(jie)連(lian)(lian)接(jie)或(huo)與泵、閥(fa)、機等管道設備的進出口管子(zi)連(lian)(lian)接(jie)使(shi)用。

  壓(ya)(ya)(ya)力(li)(li)(li)(li)(li)容器(qi)法(fa)(fa)蘭(lan)工作(zuo)原(yuan)理(li)為(wei)：當對法(fa)(fa)蘭(lan)螺栓(shuan)(shuan)(shuan)施(shi)加預(yu)緊(jin)力(li)(li)(li)(li)(li)時，螺栓(shuan)(shuan)(shuan)力(li)(li)(li)(li)(li)通過法(fa)(fa)蘭(lan)環把(ba)墊(dian)(dian)片(pian)(pian)(pian)(pian)壓(ya)(ya)(ya)緊(jin)，迫使(shi)(shi)法(fa)(fa)蘭(lan)墊(dian)(dian)片(pian)(pian)(pian)(pian)產生壓(ya)(ya)(ya)縮變(bian)形(xing)。當螺栓(shuan)(shuan)(shuan)力(li)(li)(li)(li)(li)達到(dao)一定(ding)數值(zhi)后(hou)，迫使(shi)(shi)法(fa)(fa)蘭(lan)密(mi)(mi)(mi)(mi)封(feng)(feng)面(mian)(mian)(mian)(mian)和墊(dian)(dian)片(pian)(pian)(pian)(pian)上的(de)(de)凹凸不(bu)平面(mian)(mian)(mian)(mian)借助(zhu)墊(dian)(dian)片(pian)(pian)(pian)(pian)變(bian)形(xing)而(er)填滿，這就為(wei)阻止流體(ti)介(jie)質(zhi)泄漏創(chuang)造了(le)初(chu)(chu)始密(mi)(mi)(mi)(mi)封(feng)(feng)條件。此時墊(dian)(dian)片(pian)(pian)(pian)(pian)單位有效密(mi)(mi)(mi)(mi)封(feng)(feng)面(mian)(mian)(mian)(mian)積上的(de)(de)壓(ya)(ya)(ya)緊(jin)力(li)(li)(li)(li)(li)稱為(wei)墊(dian)(dian)片(pian)(pian)(pian)(pian)的(de)(de)初(chu)(chu)始密(mi)(mi)(mi)(mi)封(feng)(feng)比壓(ya)(ya)(ya)。當設備或管道承受(shou)介(jie)質(zhi)壓(ya)(ya)(ya)力(li)(li)(li)(li)(li)后(hou)，螺栓(shuan)(shuan)(shuan)受(shou)到(dao)拉(la)伸應力(li)(li)(li)(li)(li)而(er)伸長，法(fa)(fa)蘭(lan)密(mi)(mi)(mi)(mi)封(feng)(feng)面(mian)(mian)(mian)(mian)沿著彼此分離(li)的(de)(de)方向移動(dong)，密(mi)(mi)(mi)(mi)封(feng)(feng)面(mian)(mian)(mian)(mian)與墊(dian)(dian)片(pian)(pian)(pian)(pian)之間的(de)(de)壓(ya)(ya)(ya)緊(jin)力(li)(li)(li)(li)(li)下降，墊(dian)(dian)片(pian)(pian)(pian)(pian)的(de)(de)壓(ya)(ya)(ya)縮量減(jian)少，預(yu)緊(jin)密(mi)(mi)(mi)(mi)封(feng)(feng)比壓(ya)(ya)(ya)下降。如果這時密(mi)(mi)(mi)(mi)封(feng)(feng)墊(dian)(dian)片(pian)(pian)(pian)(pian)具有足夠的(de)(de)回彈能(neng)力(li)(li)(li)(li)(li)，墊(dian)(dian)片(pian)(pian)(pian)(pian)的(de)(de)變(bian)形(xing)能(neng)補償(chang)螺栓(shuan)(shuan)(shuan)和密(mi)(mi)(mi)(mi)封(feng)(feng)面(mian)(mian)(mian)(mian)的(de)(de)分離(li)值(zhi)，而(er)使(shi)(shi)預(yu)緊(jin)密(mi)(mi)(mi)(mi)封(feng)(feng)比壓(ya)(ya)(ya)只下降到(dao)不(bu)小于工作(zuo)密(mi)(mi)(mi)(mi)封(feng)(feng)比壓(ya)(ya)(ya)，則法(fa)(fa)蘭(lan)依然保持良好的(de)(de)密(mi)(mi)(mi)(mi)封(feng)(feng)狀態。反之，如墊(dian)(dian)片(pian)(pian)(pian)(pian)的(de)(de)回彈能(neng)力(li)(li)(li)(li)(li)不(bu)足，密(mi)(mi)(mi)(mi)封(feng)(feng)比壓(ya)(ya)(ya)下降到(dao)工作(zuo)密(mi)(mi)(mi)(mi)封(feng)(feng)比壓(ya)(ya)(ya)以下，甚至密(mi)(mi)(mi)(mi)封(feng)(feng)口重新出現縫隙，則密(mi)(mi)(mi)(mi)封(feng)(feng)失效。