等(deng)(deng)徑(jing)四(si)通(tong)(tong)為(wei)管(guan)件、管(guan)道(dao)連接件。又叫(jiao)管(guan)件等(deng)(deng)徑(jing)四(si)通(tong)(tong)或者等(deng)(deng)徑(jing)四(si)通(tong)(tong)管(guan)件，等(deng)(deng)徑(jing)四(si)通(tong)(tong)接頭，用(yong)在主(zhu)管(guan)道(dao)要分(fen)支管(guan)處。

等(deng)徑(jing)(jing)四(si)(si)通(tong)(tong)(tong)有等(deng)徑(jing)(jing)和異徑(jing)(jing)之分(fen)(fen)，等(deng)徑(jing)(jing)等(deng)徑(jing)(jing)四(si)(si)通(tong)(tong)(tong)的(de)接(jie)管(guan)(guan)端部均為相同的(de)尺寸；異徑(jing)(jing)的(de)等(deng)徑(jing)(jing)四(si)(si)通(tong)(tong)(tong)的(de)主管(guan)(guan)接(jie)管(guan)(guan)尺寸相同，而支管(guan)(guan)的(de)接(jie)管(guan)(guan)尺寸小(xiao)于(yu)主管(guan)(guan)的(de)接(jie)管(guan)(guan)尺寸。等(deng)徑(jing)(jing)四(si)(si)通(tong)(tong)(tong)是用于(yu)管(guan)(guan)道分(fen)(fen)支處的(de)一種管(guan)(guan)件(jian)。對于(yu)采用無縫管(guan)(guan)制造(zao)等(deng)徑(jing)(jing)四(si)(si)通(tong)(tong)(tong)來(lai)講，目前通(tong)(tong)(tong)常所采用的(de)工藝有液壓脹形(xing)和熱壓成形(xing)兩種。

1、液壓脹形

等(deng)(deng)(deng)徑(jing)四通(tong)的(de)(de)液(ye)(ye)壓(ya)(ya)(ya)(ya)(ya)脹(zhang)(zhang)形(xing)(xing)(xing)是(shi)通(tong)過金(jin)屬材料(liao)的(de)(de)軸向補償脹(zhang)(zhang)出(chu)支管(guan)(guan)(guan)的(de)(de)一種成形(xing)(xing)(xing)工(gong)藝(yi)。其過程是(shi)采用液(ye)(ye)壓(ya)(ya)(ya)(ya)(ya)機，將與等(deng)(deng)(deng)徑(jing)四通(tong)直徑(jing)相等(deng)(deng)(deng)的(de)(de)管(guan)(guan)(guan)坯內注入液(ye)(ye)體，通(tong)過液(ye)(ye)壓(ya)(ya)(ya)(ya)(ya)機的(de)(de)兩個水平側缸同步對中(zhong)運動(dong)擠壓(ya)(ya)(ya)(ya)(ya)管(guan)(guan)(guan)坯，管(guan)(guan)(guan)坯受(shou)擠壓(ya)(ya)(ya)(ya)(ya)后體積(ji)變小，管(guan)(guan)(guan)坯內的(de)(de)液(ye)(ye)體隨(sui)管(guan)(guan)(guan)坯體積(ji)變小而(er)壓(ya)(ya)(ya)(ya)(ya)力(li)升高，當達(da)到等(deng)(deng)(deng)徑(jing)四通(tong)支管(guan)(guan)(guan)脹(zhang)(zhang)出(chu)所需要的(de)(de)壓(ya)(ya)(ya)(ya)(ya)力(li)時，金(jin)屬材料(liao)在側缸和管(guan)(guan)(guan)坯內液(ye)(ye)體壓(ya)(ya)(ya)(ya)(ya)力(li)的(de)(de)雙重作用下沿模具內腔(qiang)流動(dong)而(er)脹(zhang)(zhang)出(chu)支管(guan)(guan)(guan)。等(deng)(deng)(deng)徑(jing)四通(tong)的(de)(de)液(ye)(ye)壓(ya)(ya)(ya)(ya)(ya)脹(zhang)(zhang)形(xing)(xing)(xing)工(gong)藝(yi)可一次成形(xing)(xing)(xing)，生產(chan)效(xiao)率較(jiao)(jiao)高；等(deng)(deng)(deng)徑(jing)四通(tong)的(de)(de)主管(guan)(guan)(guan)及肩部(bu)壁厚(hou)均有增加。因無縫等(deng)(deng)(deng)徑(jing)四通(tong)的(de)(de)液(ye)(ye)壓(ya)(ya)(ya)(ya)(ya)脹(zhang)(zhang)形(xing)(xing)(xing)工(gong)藝(yi)所需的(de)(de)設(she)備(bei)噸位較(jiao)(jiao)大，目前國內主要用于(yu)小于(yu)DN400的(de)(de)標準壁厚(hou)等(deng)(deng)(deng)徑(jing)四通(tong)的(de)(de)制造。其適用的(de)(de)成形(xing)(xing)(xing)材料(liao)為冷作硬化傾向相對較(jiao)(jiao)低(di)的(de)(de)低(di)碳鋼、低(di)合金(jin)鋼、不(bu)銹鋼，包括一些有色金(jin)屬材料(liao)，如(ru)銅、鋁、鈦等(deng)(deng)(deng)。

2、熱壓成形

等徑(jing)(jing)四(si)通(tong)熱(re)壓(ya)成形(xing)是(shi)將大于(yu)等徑(jing)(jing)四(si)通(tong)直徑(jing)(jing)的(de)(de)管(guan)(guan)(guan)(guan)坯(pi)(pi)(pi)，壓(ya)扁約至等徑(jing)(jing)四(si)通(tong)直徑(jing)(jing)的(de)(de)尺(chi)寸，在拉伸支(zhi)管(guan)(guan)(guan)(guan)的(de)(de)部位(wei)(wei)開(kai)一個孔。管(guan)(guan)(guan)(guan)坯(pi)(pi)(pi)經加(jia)熱(re)，放(fang)入(ru)成形(xing)模(mo)中，并在管(guan)(guan)(guan)(guan)坯(pi)(pi)(pi)內裝(zhuang)入(ru)拉伸支(zhi)管(guan)(guan)(guan)(guan)的(de)(de)沖模(mo)；在壓(ya)力的(de)(de)作用下管(guan)(guan)(guan)(guan)坯(pi)(pi)(pi)被徑(jing)(jing)向(xiang)壓(ya)縮，在徑(jing)(jing)向(xiang)壓(ya)縮的(de)(de)過程(cheng)(cheng)中金屬向(xiang)支(zhi)管(guan)(guan)(guan)(guan)方(fang)向(xiang)流(liu)動并在沖模(mo)的(de)(de)拉伸下形(xing)成支(zhi)管(guan)(guan)(guan)(guan)。整(zheng)個過程(cheng)(cheng)是(shi)通(tong)過管(guan)(guan)(guan)(guan)坯(pi)(pi)(pi)的(de)(de)徑(jing)(jing)向(xiang)壓(ya)縮和支(zhi)管(guan)(guan)(guan)(guan)部位(wei)(wei)的(de)(de)拉伸過程(cheng)(cheng)而(er)成形(xing)。與液壓(ya)脹形(xing)等徑(jing)(jing)四(si)通(tong)不同(tong)的(de)(de)是(shi)，熱(re)壓(ya)等徑(jing)(jing)四(si)通(tong)支(zhi)管(guan)(guan)(guan)(guan)的(de)(de)金屬是(shi)由管(guan)(guan)(guan)(guan)坯(pi)(pi)(pi)的(de)(de)徑(jing)(jing)向(xiang)運動進行補償的(de)(de)，所以也(ye)稱為(wei)徑(jing)(jing)向(xiang)補償工藝(yi)。