①. 由于各國不銹(xiu)鋼管件(jian)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(zhi)管(guan)連接件(jian)的(de)選擇主要依據管(guan)道等級中已經確(que)定的(de)法蘭壓力等級或(huo)公(gong)稱壓力來選用支(zhi)管(guan)連接件(jian)。

    一般情況下，當(dang)(dang)法蘭的公稱壓力不(bu)大于(yu)(yu)PN2.5（Class 150）時(shi)，支管(guan)(guan)直接(jie)焊接(jie)在主管(guan)(guan)上；當(dang)(dang)公稱壓力不(bu)小于(yu)(yu)PN4.0（Class 300）時(shi)，則根據主管(guan)(guan)、支管(guan)(guan)公稱直徑的不(bu)同(tong)按(an)對焊三(san)通(tong)、焊接(jie)支管(guan)(guan)臺、承插(cha)焊或螺紋(wen)(wen)連接(jie)三(san)通(tong)、承插(cha)焊或螺紋(wen)(wen)支管(guan)(guan)臺的順序選(xuan)用。

  ③. 支管(guan)連接件的管(guan)子表號。

   值得注意的(de)(de)是(shi)(shi)在確定支管(guan)(guan)(guan)(guan)(guan)(guan)連接(jie)(jie)件(jian)(jian)的(de)(de)管(guan)(guan)(guan)(guan)(guan)(guan)子(zi)表(biao)(biao)號(hao)時，應(ying)根據管(guan)(guan)(guan)(guan)(guan)(guan)子(zi)與(yu)管(guan)(guan)(guan)(guan)(guan)(guan)件(jian)(jian)等強(qiang)度(du)的(de)(de)原則以及管(guan)(guan)(guan)(guan)(guan)(guan)件(jian)(jian)與(yu)管(guan)(guan)(guan)(guan)(guan)(guan)子(zi)連接(jie)(jie)方式(shi)而定。例如，當(dang)管(guan)(guan)(guan)(guan)(guan)(guan)子(zi)與(yu)管(guan)(guan)(guan)(guan)(guan)(guan)件(jian)(jian)采(cai)用對(dui)焊(han)(han)連接(jie)(jie)時，管(guan)(guan)(guan)(guan)(guan)(guan)子(zi)與(yu)不銹鋼管(guan)(guan)(guan)(guan)(guan)(guan)件(jian)(jian)的(de)(de)管(guan)(guan)(guan)(guan)(guan)(guan)子(zi)表(biao)(biao)號(hao)應(ying)一(yi)致；而當(dang)管(guan)(guan)(guan)(guan)(guan)(guan)子(zi)與(yu)管(guan)(guan)(guan)(guan)(guan)(guan)件(jian)(jian)采(cai)用承(cheng)(cheng)插(cha)焊(han)(han)或螺(luo)(luo)(luo)紋(wen)連接(jie)(jie)時，標準(zhun)的(de)(de)承(cheng)(cheng)插(cha)焊(han)(han)和螺(luo)(luo)(luo)紋(wen)管(guan)(guan)(guan)(guan)(guan)(guan)件(jian)(jian)的(de)(de)管(guan)(guan)(guan)(guan)(guan)(guan)子(zi)表(biao)(biao)號(hao)只有Sch80、Sch160、XXS三擋，最低(di)的(de)(de)管(guan)(guan)(guan)(guan)(guan)(guan)子(zi)表(biao)(biao)號(hao)就(jiu)(jiu)(jiu)是(shi)(shi)Sch80，也就(jiu)(jiu)(jiu)是(shi)(shi)說只要當(dang)承(cheng)(cheng)插(cha)焊(han)(han)或螺(luo)(luo)(luo)紋(wen)管(guan)(guan)(guan)(guan)(guan)(guan)件(jian)(jian)所連接(jie)(jie)的(de)(de)管(guan)(guan)(guan)(guan)(guan)(guan)子(zi)表(biao)(biao)號(hao)不大于Sch80時，承(cheng)(cheng)插(cha)焊(han)(han)或螺(luo)(luo)(luo)紋(wen)管(guan)(guan)(guan)(guan)(guan)(guan)件(jian)(jian)的(de)(de)管(guan)(guan)(guan)(guan)(guan)(guan)子(zi)表(biao)(biao)號(hao)就(jiu)(jiu)(jiu)選Sch80，而當(dang)所連接(jie)(jie)的(de)(de)管(guan)(guan)(guan)(guan)(guan)(guan)子(zi)表(biao)(biao)號(hao)大于Sch80時，承(cheng)(cheng)插(cha)焊(han)(han)或螺(luo)(luo)(luo)紋(wen)管(guan)(guan)(guan)(guan)(guan)(guan)件(jian)(jian)的(de)(de)管(guan)(guan)(guan)(guan)(guan)(guan)子(zi)表(biao)(biao)號(hao)就(jiu)(jiu)(jiu)選Sch160或XXS。

   另外，當對焊三(san)通(tong)主管(guan)(guan)(guan)、支管(guan)(guan)(guan)所(suo)連(lian)接的(de)管(guan)(guan)(guan)子(zi)(zi)的(de)管(guan)(guan)(guan)子(zi)(zi)表號(hao)不同(tong)(tong)時，應(ying)注(zhu)意三(san)通(tong)主管(guan)(guan)(guan)、支管(guan)(guan)(guan)端部的(de)管(guan)(guan)(guan)子(zi)(zi)表號(hao)應(ying)分別與其所(suo)連(lian)接的(de)管(guan)(guan)(guan)子(zi)(zi)的(de)管(guan)(guan)(guan)子(zi)(zi)表號(hao)相同(tong)(tong)，這(zhe)樣就非常方便(bian)管(guan)(guan)(guan)道施(shi)工，管(guan)(guan)(guan)件不必現場(chang)再打坡口(kou)。

   值得(de)注意的(de)是(shi)選用(yong)支管(guan)直接焊(han)接在主管(guan)上這一種連接形(xing)式，要核算(suan)管(guan)子是(shi)否(fou)需要補(bu)(bu)強。支管(guan)補(bu)(bu)強的(de)方法(fa)在ASME B31.3、SH／T 3059《石(shi)油(you)化工(gong)管(guan)道(dao)(dao)設(she)計(ji)器材選用(yong)規(gui)范(fan)》、GB50316《工(gong)業金屬管(guan)道(dao)(dao)設(she)計(ji)規(gui)范(fan)》、GB／T 20801《壓力管(guan)道(dao)(dao)規(gui)范(fan)工(gong)業管(guan)道(dao)(dao)》等(deng)標準規(gui)范(fan)中均有(you)詳細(xi)的(de)介(jie)紹。