有熱彎管和冷彎彎管兩種。有色金屬管、小口徑的不銹鋼管，一般采用冷彎；鋁錳合金管不得冷彎；碳鋼管冷彎和熱彎均可。

  彎(wan)(wan)(wan)管(guan)管(guan)徑(jing)(jing)較(jiao)大(da)或管(guan)壁較(jiao)薄的管(guan)子(zi)，應(ying)(ying)采(cai)用(yong)(yong)較(jiao)大(da)的彎(wan)(wan)(wan)曲(qu)半徑(jing)(jing)；彎(wan)(wan)(wan)曲(qu)管(guan)徑(jing)(jing)較(jiao)小或管(guan)壁較(jiao)厚的管(guan)子(zi)，可采(cai)用(yong)(yong)較(jiao)小的彎(wan)(wan)(wan)曲(qu)半徑(jing)(jing)。彎(wan)(wan)(wan)管(guan)的最(zui)小彎(wan)(wan)(wan)曲(qu)半徑(jing)(jing)應(ying)(ying)符合表 2-5 的規定(ding)。

 彎(wan)制(zhi)有(you)焊縫(feng)(feng)的(de)管子時(shi)，其縱焊縫(feng)(feng)應置于(yu)居(ju)中(zhong)軸線(xian)45°的(de)地(di)方，即在(zai)彎(wan)曲平(ping)面的(de)上方或下方，不得放(fang)在(zai)彎(wan)曲的(de)內(nei)側或外側。彎(wan)管的(de)主要(yao)形式如(ru)圖 2-22所示(shi)。

 不銹鋼(gang)管(guan)(guan)(guan)(guan)彎(wan)曲時(shi)，由(you)于管(guan)(guan)(guan)(guan)子內外側管(guan)(guan)(guan)(guan)壁厚的變(bian)(bian)化，使(shi)得彎(wan)曲截面(mian)由(you)原來的圓(yuan)(yuan)形(xing)變(bian)(bian)成(cheng)了橢(tuo)圓(yuan)(yuan)形(xing)，如(ru)圖 2-23所示。為了使(shi)過流斷面(mian)縮(suo)小(xiao)不致過小(xiao)，一(yi)般(ban)對彎(wan)管(guan)(guan)(guan)(guan)的橢(tuo)圓(yuan)(yuan)率規定(ding)為高壓(ya)管(guan)(guan)(guan)(guan)不得超過5%，中、低壓(ya)管(guan)(guan)(guan)(guan)不得超過8%，銅、鋁管(guan)(guan)(guan)(guan)不得超過9%、煨制(zhi)彎(wan)管(guan)(guan)(guan)(guan)應光(guang)滑圓(yuan)(yuan)整(zheng)，不應有皺褶、分(fen)層、過燒等缺陷。