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(feng)頭是(shi)常(chang)壓(ya)及承壓(ya)容(rong)器中不(bu)可或缺的零(ling)部件，廣泛用于石油、電子(zi)、供暖、化工、醫藥、污水處理、輕紡(fang)、食品、機械、建(jian)筑、核電、航(hang)空(kong)航(hang)天、壓(ya)力容(rong)器、軍工等行業。

封頭是壓(ya)(ya)力容(rong)(rong)(rong)器的重要受壓(ya)(ya)元件之一，它不但直接(jie)影響容(rong)(rong)(rong)器的制造(zao)質量和(he)成本，而且還影響生產裝置的安全和(he)長期運行。常用的裝置有反應壓(ya)(ya)力容(rong)(rong)(rong)器，熱交換壓(ya)(ya)力容(rong)(rong)(rong)器，分(fen)離(li)壓(ya)(ya)力容(rong)(rong)(rong)器，儲存壓(ya)(ya)力容(rong)(rong)(rong)器等等。

 封(feng)頭(tou)(tou)(tou)的種類(lei)繁多，按用途可(ke)分(fen)為(wei)承壓封(feng)頭(tou)(tou)(tou)和(he)常壓封(feng)頭(tou)(tou)(tou)，按形(xing)(xing)(xing)(xing)狀可(ke)分(fen)為(wei)橢圓封(feng)頭(tou)(tou)(tou)、蝶形(xing)(xing)(xing)(xing)封(feng)頭(tou)(tou)(tou)、球冠(guan)形(xing)(xing)(xing)(xing)封(feng)頭(tou)(tou)(tou)、半球形(xing)(xing)(xing)(xing)封(feng)頭(tou)(tou)(tou)、弓形(xing)(xing)(xing)(xing)封(feng)頭(tou)(tou)(tou)、平(ping)底形(xing)(xing)(xing)(xing)封(feng)頭(tou)(tou)(tou)、錐形(xing)(xing)(xing)(xing)封(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(dui)(dui)于非(fei)對(dui)(dui)稱形(xing)狀的(de)(de)(de)工(gong)件(jian)，橢(tuo)圓(yuan)型封(feng)頭和各種型式的(de)(de)(de)罩子，可使(shi)用(yong)熱(re)沖(chong)壓(ya)法進行加工(gong)成(cheng)(cheng)型。當然(ran)，熱(re)沖(chong)壓(ya)也適用(yong)于所(suo)有對(dui)(dui)稱形(xing)狀的(de)(de)(de)封(feng)頭成(cheng)(cheng)型。目前，使(shi)用(yong)的(de)(de)(de)大型沖(chong)壓(ya)成(cheng)(cheng)型設備的(de)(de)(de)加工(gong)尺(chi)寸(cun)范圍都較(jiao)大，能(neng)加工(gong)成(cheng)(cheng)型的(de)(de)(de)外徑達(da)29.261m、厚(hou)達(da)12.7mm的(de)(de)(de)封(feng)頭。對(dui)(dui)某(mou)些尺(chi)寸(cun)和形(xing)狀，壁厚(hou)76.2mm的(de)(de)(de)工(gong)件(jian)也可沖(chong)壓(ya)成(cheng)(cheng)型。

封(feng)頭成型常用的(de)方法有沖壓(ya)(ya)成型、旋壓(ya)(ya)成型和爆炸成型。封(feng)頭沖壓(ya)(ya)成型工藝流(liu)程(cheng)：材料(liao)檢(jian)驗(yan)→劃線→切(qie)割下料(liao)→(厚(hou)度≥6mm的(de)坡口加工）→組裝對(dui)焊（焊縫修磨）→加熱→沖壓(ya)(ya)→余量切(qie)割→檢(jian)查驗(yan)收。