四(si)氟四(si)通(tong)(tong)(tong)有等徑(jing)(jing)(jing)(jing)和(he)異徑(jing)(jing)(jing)(jing)之(zhi)分，等徑(jing)(jing)(jing)(jing)四(si)通(tong)(tong)(tong)的(de)接(jie)管(guan)(guan)(guan)(guan)端(duan)部(bu)(bu)均為相(xiang)同的(de)尺寸(cun)(cun)(cun)(cun)；異徑(jing)(jing)(jing)(jing)的(de)四(si)通(tong)(tong)(tong)的(de)主(zhu)管(guan)(guan)(guan)(guan)接(jie)管(guan)(guan)(guan)(guan)尺寸(cun)(cun)(cun)(cun)相(xiang)同，而(er)支(zhi)(zhi)管(guan)(guan)(guan)(guan)的(de)接(jie)管(guan)(guan)(guan)(guan)尺寸(cun)(cun)(cun)(cun)小于主(zhu)管(guan)(guan)(guan)(guan)的(de)接(jie)管(guan)(guan)(guan)(guan)尺寸(cun)(cun)(cun)(cun)。四(si)通(tong)(tong)(tong)是用于管(guan)(guan)(guan)(guan)道分支(zhi)(zhi)處的(de)一(yi)(yi)種管(guan)(guan)(guan)(guan)件。四(si)氟四(si)通(tong)(tong)(tong)熱(re)壓(ya)成形是將大于四(si)通(tong)(tong)(tong)直徑(jing)(jing)(jing)(jing)的(de)管(guan)(guan)(guan)(guan)坯(pi)，壓(ya)扁約(yue)至四(si)通(tong)(tong)(tong)直徑(jing)(jing)(jing)(jing)的(de)尺寸(cun)(cun)(cun)(cun)，在拉(la)伸支(zhi)(zhi)管(guan)(guan)(guan)(guan)的(de)部(bu)(bu)位開一(yi)(yi)個孔；管(guan)(guan)(guan)(guan)坯(pi)經加熱(re)，放入(ru)成形模(mo)中，并在管(guan)(guan)(guan)(guan)坯(pi)內裝(zhuang)入(ru)拉(la)伸支(zhi)(zhi)管(guan)(guan)(guan)(guan)的(de)沖模(mo)；在壓(ya)力(li)的(de)作(zuo)用下管(guan)(guan)(guan)(guan)坯(pi)被(bei)徑(jing)(jing)(jing)(jing)向(xiang)壓(ya)縮，在徑(jing)(jing)(jing)(jing)向(xiang)壓(ya)縮的(de)過(guo)程中金屬向(xiang)支(zhi)(zhi)管(guan)(guan)(guan)(guan)方向(xiang)流(liu)動并在沖模(mo)的(de)拉(la)伸下形成支(zhi)(zhi)管(guan)(guan)(guan)(guan)。整個過(guo)程是通(tong)(tong)(tong)過(guo)管(guan)(guan)(guan)(guan)坯(pi)的(de)徑(jing)(jing)(jing)(jing)向(xiang)壓(ya)縮和(he)支(zhi)(zhi)管(guan)(guan)(guan)(guan)部(bu)(bu)位的(de)拉(la)伸過(guo)程而(er)成形。