‌ 偏(pian)心(xin)異(yi)徑(jing)管(guan)又(you)叫(jiao)偏(pian)心(xin)大(dai)小(xiao)頭(tou)是(shi)管(guan)道(dao)變(bian)徑(jing)管(guan)件(jian)之(zhi)一(yi)，在(zai)管(guan)道(dao)施(shi)工(gong)中(zhong)用(yong)於(yu)兩(liang)種(zhong)不(bu)同(tong)管(guan)徑(jing)的(di)連(lian)接(jie)，它(ta)的(di)設(she)計(ji)使(shi)得(dei)兩(liang)個(ge)管(guan)子(zi)的(di)中(zhong)心(xin)軸(zhou)線(xian)不(bu)相(xiang)交(jiao)而(er)偏(pian)離(li)。偏(pian)心(xin)異(yi)徑(jing)管(guan)采(cai)用(yong)縮(suo)徑(jing)壓(ya)製(zhi)、擴(kuo)徑(jing)壓(ya)製(zhi)或(huo)縮(suo)徑(jing)加(jia)擴(kuo)徑(jing)壓(ya)製(zhi)等(deng)成(cheng)形(xing)工(gong)藝(yi)，也(ye)可(ke)用(yong)無(wu)縫(feng)管(guan)衝(chong)壓(ya)成(cheng)形(xing)。異(yi)徑(jing)管(guan)按(an)照(zhao)形(xing)狀(zhuang)的(di)不(bu)同(tong)可(ke)以(yi)分(fen)為(wei)RC同(tong)心(xin)異(yi)徑(jing)管(guan)和(hu)RE偏(pian)心(xin)異(yi)徑(jing)管(guan)，當(dang)管(guan)道(dao)中(zhong)流(liu)體(ti)的(di)流(liu)量(liang)有(you)變(bian)化(hua)時(shi)，比(bi)如(ru)增(zeng)大(dai)或(huo)減(jian)少(shao)，流(liu)速(su)要(yao)求(qiu)變(bian)化(hua)不(bu)大(dai)時(shi)均(jun)需(xu)采(cai)用(yong)異(yi)徑(jing)管(guan)。偏(pian)心(xin)異(yi)徑(jing)管(guan)主(zhu)要(yao)應(ying)用(yong)在(zai)石(dan)油(you)、化(hua)工(gong)、天(tian)然(ran)氣(qi)、蒸(zheng)汽(qi)管(guan)網(wang)、汙(wu)水(shui)管(guan)道(dao)、液(ye)壓(ya)機(ji)械(xie)等(deng)基(ji)礎(chu)工(gong)程(cheng)。