顧名思義，封頭就是容器的兩端的端蓋。所以，封頭一般都是用于與各種筒體的配對后，組成壓力容器。

 封頭是(shi)常(chang)壓及承壓容(rong)器中不可或缺(que)的(de)零部件，廣泛用于石油、電子、供暖、化(hua)工、醫藥、污(wu)水處(chu)理、輕(qing)紡(fang)、食品、機械、建筑、核電、航空航天、壓力(li)容(rong)器、軍工等行業。

封(feng)頭是壓(ya)(ya)力容(rong)(rong)(rong)器的重(zhong)要(yao)受壓(ya)(ya)元件之一(yi)，它不但(dan)直接(jie)影響容(rong)(rong)(rong)器的制(zhi)造質量和(he)成本，而且還影響生產(chan)裝置的安全和(he)長(chang)期(qi)運行。常(chang)用的裝置有反應壓(ya)(ya)力容(rong)(rong)(rong)器，熱交換壓(ya)(ya)力容(rong)(rong)(rong)器，分離壓(ya)(ya)力容(rong)(rong)(rong)器，儲存壓(ya)(ya)力容(rong)(rong)(rong)器等等。

 封(feng)(feng)頭(tou)(tou)(tou)的種(zhong)類繁多，按(an)用途可(ke)分(fen)為(wei)承壓封(feng)(feng)頭(tou)(tou)(tou)和常(chang)壓封(feng)(feng)頭(tou)(tou)(tou)，按(an)形(xing)(xing)狀可(ke)分(fen)為(wei)橢圓封(feng)(feng)頭(tou)(tou)(tou)、蝶(die)形(xing)(xing)封(feng)(feng)頭(tou)(tou)(tou)、球(qiu)冠形(xing)(xing)封(feng)(feng)頭(tou)(tou)(tou)、半球(qiu)形(xing)(xing)封(feng)(feng)頭(tou)(tou)(tou)、弓形(xing)(xing)封(feng)(feng)頭(tou)(tou)(tou)、平底形(xing)(xing)封(feng)(feng)頭(tou)(tou)(tou)、錐形(xing)(xing)封(feng)(feng)頭(tou)(tou)(tou)等。

 圖4-29是材質為06Cr19Ni10各種規格的標準橢圓形封頭。

 對于非對稱形狀(zhuang)的(de)工件(jian)，橢(tuo)圓型(xing)封頭(tou)(tou)和各種型(xing)式(shi)的(de)罩子，可使(shi)用(yong)(yong)熱沖(chong)壓(ya)法進行加工成型(xing)。當然，熱沖(chong)壓(ya)也(ye)適(shi)用(yong)(yong)于所有(you)對稱形狀(zhuang)的(de)封頭(tou)(tou)成型(xing)。目前(qian)，使(shi)用(yong)(yong)的(de)大型(xing)沖(chong)壓(ya)成型(xing)設備的(de)加工尺寸(cun)(cun)范圍(wei)都較大，能加工成型(xing)的(de)外徑(jing)達(da)(da)29.261m、厚(hou)達(da)(da)12.7mm的(de)封頭(tou)(tou)。對某些(xie)尺寸(cun)(cun)和形狀(zhuang)，壁厚(hou)76.2mm的(de)工件(jian)也(ye)可沖(chong)壓(ya)成型(xing)。

封頭成(cheng)(cheng)型常(chang)用的方(fang)法有沖壓(ya)(ya)成(cheng)(cheng)型、旋壓(ya)(ya)成(cheng)(cheng)型和爆炸(zha)成(cheng)(cheng)型。封頭沖壓(ya)(ya)成(cheng)(cheng)型工藝流程(cheng)：材(cai)料(liao)檢驗→劃線(xian)→切(qie)割下料(liao)→(厚度≥6mm的坡口(kou)加工）→組裝(zhuang)對焊（焊縫修磨）→加熱→沖壓(ya)(ya)→余量切(qie)割→檢查驗收。