①. 由于各國不銹(xiu)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)連接(jie)(jie)件(jian)的選擇主要依據管(guan)道(dao)等(deng)級中已經確定(ding)的法(fa)蘭(lan)壓力(li)等(deng)級或公稱壓力(li)來選用(yong)支管(guan)連接(jie)(jie)件(jian)。

    一般情況下，當法蘭的公稱(cheng)壓力(li)(li)不(bu)大于(yu)PN2.5（Class 150）時，支(zhi)管直(zhi)(zhi)接(jie)焊接(jie)在主管上；當公稱(cheng)壓力(li)(li)不(bu)小于(yu)PN4.0（Class 300）時，則根據主管、支(zhi)管公稱(cheng)直(zhi)(zhi)徑的不(bu)同按對焊三通、焊接(jie)支(zhi)管臺(tai)、承插焊或(huo)螺紋連接(jie)三通、承插焊或(huo)螺紋支(zhi)管臺(tai)的順序選用。

  ③. 支管(guan)(guan)連接件的(de)管(guan)(guan)子表號。

   值得注意的(de)(de)是(shi)在確定(ding)支管(guan)(guan)(guan)連(lian)接(jie)件(jian)(jian)(jian)的(de)(de)管(guan)(guan)(guan)子(zi)(zi)(zi)表號(hao)(hao)時(shi)，應根據管(guan)(guan)(guan)子(zi)(zi)(zi)與(yu)(yu)管(guan)(guan)(guan)件(jian)(jian)(jian)等強度的(de)(de)原則以及管(guan)(guan)(guan)件(jian)(jian)(jian)與(yu)(yu)管(guan)(guan)(guan)子(zi)(zi)(zi)連(lian)接(jie)方式而定(ding)。例如，當管(guan)(guan)(guan)子(zi)(zi)(zi)與(yu)(yu)管(guan)(guan)(guan)件(jian)(jian)(jian)采用(yong)對(dui)焊(han)(han)(han)連(lian)接(jie)時(shi)，管(guan)(guan)(guan)子(zi)(zi)(zi)與(yu)(yu)不銹(xiu)鋼管(guan)(guan)(guan)件(jian)(jian)(jian)的(de)(de)管(guan)(guan)(guan)子(zi)(zi)(zi)表號(hao)(hao)應一(yi)致；而當管(guan)(guan)(guan)子(zi)(zi)(zi)與(yu)(yu)管(guan)(guan)(guan)件(jian)(jian)(jian)采用(yong)承插焊(han)(han)(han)或(huo)螺(luo)(luo)紋(wen)連(lian)接(jie)時(shi)，標準的(de)(de)承插焊(han)(han)(han)和螺(luo)(luo)紋(wen)管(guan)(guan)(guan)件(jian)(jian)(jian)的(de)(de)管(guan)(guan)(guan)子(zi)(zi)(zi)表號(hao)(hao)只有Sch80、Sch160、XXS三擋，最低的(de)(de)管(guan)(guan)(guan)子(zi)(zi)(zi)表號(hao)(hao)就(jiu)是(shi)Sch80，也(ye)就(jiu)是(shi)說只要當承插焊(han)(han)(han)或(huo)螺(luo)(luo)紋(wen)管(guan)(guan)(guan)件(jian)(jian)(jian)所(suo)連(lian)接(jie)的(de)(de)管(guan)(guan)(guan)子(zi)(zi)(zi)表號(hao)(hao)不大(da)(da)于Sch80時(shi)，承插焊(han)(han)(han)或(huo)螺(luo)(luo)紋(wen)管(guan)(guan)(guan)件(jian)(jian)(jian)的(de)(de)管(guan)(guan)(guan)子(zi)(zi)(zi)表號(hao)(hao)就(jiu)選Sch80，而當所(suo)連(lian)接(jie)的(de)(de)管(guan)(guan)(guan)子(zi)(zi)(zi)表號(hao)(hao)大(da)(da)于Sch80時(shi)，承插焊(han)(han)(han)或(huo)螺(luo)(luo)紋(wen)管(guan)(guan)(guan)件(jian)(jian)(jian)的(de)(de)管(guan)(guan)(guan)子(zi)(zi)(zi)表號(hao)(hao)就(jiu)選Sch160或(huo)XXS。

   另外，當對焊三通(tong)主(zhu)管(guan)(guan)(guan)(guan)、支管(guan)(guan)(guan)(guan)所連(lian)(lian)接的(de)管(guan)(guan)(guan)(guan)子(zi)(zi)的(de)管(guan)(guan)(guan)(guan)子(zi)(zi)表號不(bu)同時(shi)，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)(zi)表號應分別與其所連(lian)(lian)接的(de)管(guan)(guan)(guan)(guan)子(zi)(zi)的(de)管(guan)(guan)(guan)(guan)子(zi)(zi)表號相同，這樣就非(fei)常方便(bian)管(guan)(guan)(guan)(guan)道(dao)施工，管(guan)(guan)(guan)(guan)件不(bu)必現場再打坡口。

   值得注意的(de)是(shi)選用支管(guan)(guan)直接焊接在主管(guan)(guan)上這(zhe)一種(zhong)連接形(xing)式(shi)，要核算管(guan)(guan)子(zi)是(shi)否(fou)需要補強。支管(guan)(guan)補強的(de)方法(fa)在ASME B31.3、SH／T 3059《石油化工管(guan)(guan)道設計器材(cai)選用規(gui)范(fan)》、GB50316《工業(ye)(ye)金屬管(guan)(guan)道設計規(gui)范(fan)》、GB／T 20801《壓力管(guan)(guan)道規(gui)范(fan)工業(ye)(ye)管(guan)(guan)道》等標準規(gui)范(fan)中均有詳細的(de)介紹。