①. 由于各國不銹鋼管件標準化程度不同，分支管連接方式及管件的選擇也不盡相同。一般情況下，支管連接多采用成型支管連接件、焊接的引出口連接件以及支管直接焊接在主管上等連接形式。

  ②. 支管(guan)(guan)連接(jie)件的選擇主要(yao)依(yi)據(ju)管(guan)(guan)道等級中已經確定的法蘭壓(ya)力等級或公(gong)稱壓(ya)力來選用支管(guan)(guan)連接(jie)件。

    一般情況(kuang)下，當法蘭的公稱壓力(li)不(bu)(bu)大于PN2.5（Class 150）時，支(zhi)管(guan)直(zhi)接(jie)(jie)焊(han)(han)接(jie)(jie)在主(zhu)(zhu)管(guan)上；當公稱壓力(li)不(bu)(bu)小于PN4.0（Class 300）時，則根據主(zhu)(zhu)管(guan)、支(zhi)管(guan)公稱直(zhi)徑的不(bu)(bu)同按對焊(han)(han)三通(tong)、焊(han)(han)接(jie)(jie)支(zhi)管(guan)臺、承插(cha)(cha)焊(han)(han)或(huo)螺紋連(lian)接(jie)(jie)三通(tong)、承插(cha)(cha)焊(han)(han)或(huo)螺紋支(zhi)管(guan)臺的順序(xu)選用。

  ③. 支管連接件(jian)的管子表號(hao)。

   值得注(zhu)意(yi)的(de)(de)(de)是(shi)(shi)在確定支管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)連(lian)接件(jian)(jian)的(de)(de)(de)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)子(zi)表(biao)號(hao)時(shi)，應(ying)根據管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)子(zi)與管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)件(jian)(jian)等強度的(de)(de)(de)原則以及管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)件(jian)(jian)與管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)子(zi)連(lian)接方式而定。例如，當(dang)(dang)(dang)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)子(zi)與管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)件(jian)(jian)采(cai)(cai)用對(dui)焊(han)(han)連(lian)接時(shi)，管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)子(zi)與不(bu)銹鋼管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)件(jian)(jian)的(de)(de)(de)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)子(zi)表(biao)號(hao)應(ying)一致；而當(dang)(dang)(dang)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)子(zi)與管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)件(jian)(jian)采(cai)(cai)用承(cheng)(cheng)插(cha)焊(han)(han)或(huo)(huo)螺紋(wen)連(lian)接時(shi)，標準的(de)(de)(de)承(cheng)(cheng)插(cha)焊(han)(han)和螺紋(wen)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)件(jian)(jian)的(de)(de)(de)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)子(zi)表(biao)號(hao)只有Sch80、Sch160、XXS三擋(dang)，最低的(de)(de)(de)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)子(zi)表(biao)號(hao)就(jiu)是(shi)(shi)Sch80，也就(jiu)是(shi)(shi)說(shuo)只要當(dang)(dang)(dang)承(cheng)(cheng)插(cha)焊(han)(han)或(huo)(huo)螺紋(wen)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)件(jian)(jian)所(suo)連(lian)接的(de)(de)(de)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)子(zi)表(biao)號(hao)不(bu)大于Sch80時(shi)，承(cheng)(cheng)插(cha)焊(han)(han)或(huo)(huo)螺紋(wen)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)件(jian)(jian)的(de)(de)(de)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)子(zi)表(biao)號(hao)就(jiu)選(xuan)Sch80，而當(dang)(dang)(dang)所(suo)連(lian)接的(de)(de)(de)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)子(zi)表(biao)號(hao)大于Sch80時(shi)，承(cheng)(cheng)插(cha)焊(han)(han)或(huo)(huo)螺紋(wen)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)件(jian)(jian)的(de)(de)(de)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)子(zi)表(biao)號(hao)就(jiu)選(xuan)Sch160或(huo)(huo)XXS。

   另外，當(dang)對(dui)焊(han)三通(tong)主(zhu)管(guan)(guan)(guan)(guan)、支管(guan)(guan)(guan)(guan)所連接的(de)管(guan)(guan)(guan)(guan)子(zi)的(de)管(guan)(guan)(guan)(guan)子(zi)表(biao)號(hao)不同時，應注意(yi)三通(tong)主(zhu)管(guan)(guan)(guan)(guan)、支管(guan)(guan)(guan)(guan)端部的(de)管(guan)(guan)(guan)(guan)子(zi)表(biao)號(hao)應分別與其所連接的(de)管(guan)(guan)(guan)(guan)子(zi)的(de)管(guan)(guan)(guan)(guan)子(zi)表(biao)號(hao)相同，這樣就非(fei)常(chang)方便管(guan)(guan)(guan)(guan)道施(shi)工，管(guan)(guan)(guan)(guan)件(jian)不必現場再打坡口。

   值得注意的(de)是選(xuan)用支管直接(jie)焊接(jie)在(zai)主管上這一種連接(jie)形式(shi)，要核(he)算管子是否需要補(bu)(bu)強(qiang)。支管補(bu)(bu)強(qiang)的(de)方法在(zai)ASME B31.3、SH／T 3059《石油化(hua)工管道(dao)(dao)(dao)設計(ji)器材(cai)選(xuan)用規(gui)范(fan)》、GB50316《工業(ye)(ye)金屬(shu)管道(dao)(dao)(dao)設計(ji)規(gui)范(fan)》、GB／T 20801《壓力管道(dao)(dao)(dao)規(gui)范(fan)工業(ye)(ye)管道(dao)(dao)(dao)》等標準規(gui)范(fan)中均有詳細的(de)介紹。