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。

 封頭是常壓及(ji)承壓容器(qi)中不可或(huo)缺(que)的零部(bu)件，廣泛用(yong)于石油、電子、供(gong)暖、化工、醫藥、污(wu)水處理、輕紡、食品(pin)、機械、建(jian)筑、核電、航空航天、壓力容器(qi)、軍工等行業。

封頭是壓(ya)力(li)容(rong)(rong)(rong)器的重要受壓(ya)元件之(zhi)一，它不(bu)但直接影響容(rong)(rong)(rong)器的制造質量(liang)和(he)(he)成本，而且還影響生(sheng)產裝(zhuang)置的安全(quan)和(he)(he)長(chang)期(qi)運行。常(chang)用的裝(zhuang)置有反(fan)應壓(ya)力(li)容(rong)(rong)(rong)器，熱交換(huan)壓(ya)力(li)容(rong)(rong)(rong)器，分離壓(ya)力(li)容(rong)(rong)(rong)器，儲存壓(ya)力(li)容(rong)(rong)(rong)器等等。

 封(feng)(feng)頭(tou)的種類繁多，按用途可分為(wei)承壓(ya)封(feng)(feng)頭(tou)和常(chang)壓(ya)封(feng)(feng)頭(tou)，按形(xing)(xing)(xing)狀可分為(wei)橢圓封(feng)(feng)頭(tou)、蝶形(xing)(xing)(xing)封(feng)(feng)頭(tou)、球冠形(xing)(xing)(xing)封(feng)(feng)頭(tou)、半球形(xing)(xing)(xing)封(feng)(feng)頭(tou)、弓形(xing)(xing)(xing)封(feng)(feng)頭(tou)、平底(di)形(xing)(xing)(xing)封(feng)(feng)頭(tou)、錐(zhui)形(xing)(xing)(xing)封(feng)(feng)頭(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(yu)非對(dui)(dui)稱(cheng)形(xing)狀(zhuang)(zhuang)的(de)(de)工件，橢(tuo)圓型(xing)(xing)封(feng)頭(tou)和(he)各種型(xing)(xing)式(shi)的(de)(de)罩子，可(ke)使用熱沖(chong)(chong)壓法進(jin)行加(jia)工成(cheng)(cheng)(cheng)型(xing)(xing)。當然，熱沖(chong)(chong)壓也適(shi)用于(yu)所(suo)有對(dui)(dui)稱(cheng)形(xing)狀(zhuang)(zhuang)的(de)(de)封(feng)頭(tou)成(cheng)(cheng)(cheng)型(xing)(xing)。目前(qian)，使用的(de)(de)大(da)型(xing)(xing)沖(chong)(chong)壓成(cheng)(cheng)(cheng)型(xing)(xing)設(she)備(bei)的(de)(de)加(jia)工尺寸(cun)范圍都較大(da)，能加(jia)工成(cheng)(cheng)(cheng)型(xing)(xing)的(de)(de)外徑達29.261m、厚達12.7mm的(de)(de)封(feng)頭(tou)。對(dui)(dui)某些尺寸(cun)和(he)形(xing)狀(zhuang)(zhuang)，壁厚76.2mm的(de)(de)工件也可(ke)沖(chong)(chong)壓成(cheng)(cheng)(cheng)型(xing)(xing)。

封(feng)頭成(cheng)型(xing)常(chang)用的(de)方法有沖(chong)壓成(cheng)型(xing)、旋壓成(cheng)型(xing)和爆(bao)炸(zha)成(cheng)型(xing)。封(feng)頭沖(chong)壓成(cheng)型(xing)工(gong)藝流程：材料檢(jian)驗(yan)→劃線(xian)→切割(ge)下料→(厚度≥6mm的(de)坡口加工(gong)）→組裝對焊（焊縫修磨）→加熱→沖(chong)壓→余量切割(ge)→檢(jian)查驗(yan)收。