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。

 封頭是常(chang)壓及(ji)承(cheng)壓容器中不可或缺的零(ling)部件，廣(guang)泛(fan)用于石油(you)、電子、供暖、化工(gong)(gong)、醫藥、污水處理(li)、輕紡、食品、機械、建筑、核(he)電、航(hang)空(kong)航(hang)天(tian)、壓力容器、軍(jun)工(gong)(gong)等行(xing)業。

封頭是壓(ya)(ya)(ya)力(li)容(rong)器的(de)重要(yao)受壓(ya)(ya)(ya)元件之一，它不(bu)但直(zhi)接影響容(rong)器的(de)制造(zao)質量和成本，而且還(huan)影響生(sheng)產裝置的(de)安全和長期運(yun)行。常用(yong)的(de)裝置有(you)反(fan)應壓(ya)(ya)(ya)力(li)容(rong)器，熱交換壓(ya)(ya)(ya)力(li)容(rong)器，分離(li)壓(ya)(ya)(ya)力(li)容(rong)器，儲存壓(ya)(ya)(ya)力(li)容(rong)器等等。

 封(feng)(feng)(feng)(feng)頭(tou)(tou)的種(zhong)類繁多，按用途可分為(wei)承壓封(feng)(feng)(feng)(feng)頭(tou)(tou)和常壓封(feng)(feng)(feng)(feng)頭(tou)(tou)，按形(xing)狀(zhuang)可分為(wei)橢圓封(feng)(feng)(feng)(feng)頭(tou)(tou)、蝶(die)形(xing)封(feng)(feng)(feng)(feng)頭(tou)(tou)、球冠(guan)形(xing)封(feng)(feng)(feng)(feng)頭(tou)(tou)、半球形(xing)封(feng)(feng)(feng)(feng)頭(tou)(tou)、弓形(xing)封(feng)(feng)(feng)(feng)頭(tou)(tou)、平(ping)底形(xing)封(feng)(feng)(feng)(feng)頭(tou)(tou)、錐形(xing)封(feng)(feng)(feng)(feng)頭(tou)(tou)等(deng)。

 圖4-29是材質為06Cr19Ni10各種規格的標準橢圓形封頭。

 對(dui)于非對(dui)稱(cheng)形(xing)狀(zhuang)的(de)(de)工件(jian)(jian)，橢圓型(xing)封頭(tou)和(he)各種型(xing)式的(de)(de)罩(zhao)子，可使(shi)用熱沖(chong)壓法進行加(jia)工成(cheng)(cheng)型(xing)。當然，熱沖(chong)壓也(ye)適用于所有對(dui)稱(cheng)形(xing)狀(zhuang)的(de)(de)封頭(tou)成(cheng)(cheng)型(xing)。目前，使(shi)用的(de)(de)大(da)型(xing)沖(chong)壓成(cheng)(cheng)型(xing)設備的(de)(de)加(jia)工尺寸范(fan)圍都較大(da)，能加(jia)工成(cheng)(cheng)型(xing)的(de)(de)外(wai)徑達29.261m、厚達12.7mm的(de)(de)封頭(tou)。對(dui)某些(xie)尺寸和(he)形(xing)狀(zhuang)，壁(bi)厚76.2mm的(de)(de)工件(jian)(jian)也(ye)可沖(chong)壓成(cheng)(cheng)型(xing)。

封頭(tou)成(cheng)型(xing)(xing)(xing)常用的(de)方法有沖(chong)壓(ya)(ya)成(cheng)型(xing)(xing)(xing)、旋壓(ya)(ya)成(cheng)型(xing)(xing)(xing)和爆炸(zha)成(cheng)型(xing)(xing)(xing)。封頭(tou)沖(chong)壓(ya)(ya)成(cheng)型(xing)(xing)(xing)工藝流程：材料檢(jian)驗→劃(hua)線→切(qie)割下料→(厚度(du)≥6mm的(de)坡口加工）→組裝對焊（焊縫修(xiu)磨）→加熱→沖(chong)壓(ya)(ya)→余量切(qie)割→檢(jian)查驗收。