①. 由于各國不銹鋼(gang)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)(guan)連接(jie)件(jian)的(de)選擇(ze)主要依據(ju)管(guan)(guan)道等(deng)級(ji)中已經確定(ding)的(de)法蘭壓力等(deng)級(ji)或公稱壓力來(lai)選用(yong)支(zhi)管(guan)(guan)連接(jie)件(jian)。

    一般情況下，當法蘭(lan)的(de)(de)公(gong)稱(cheng)(cheng)壓力不(bu)(bu)(bu)大于PN2.5（Class 150）時，支(zhi)管(guan)(guan)直接焊(han)接在主(zhu)管(guan)(guan)上(shang)；當公(gong)稱(cheng)(cheng)壓力不(bu)(bu)(bu)小于PN4.0（Class 300）時，則根據(ju)主(zhu)管(guan)(guan)、支(zhi)管(guan)(guan)公(gong)稱(cheng)(cheng)直徑的(de)(de)不(bu)(bu)(bu)同按對焊(han)三通、焊(han)接支(zhi)管(guan)(guan)臺(tai)、承插(cha)焊(han)或螺紋(wen)連接三通、承插(cha)焊(han)或螺紋(wen)支(zhi)管(guan)(guan)臺(tai)的(de)(de)順序(xu)選用。

  ③. 支管連接件的管子表(biao)號。

   值得注意的(de)(de)是(shi)在確定支管(guan)(guan)(guan)(guan)(guan)(guan)連接(jie)件(jian)(jian)(jian)的(de)(de)管(guan)(guan)(guan)(guan)(guan)(guan)子(zi)(zi)(zi)(zi)(zi)表(biao)(biao)號(hao)時(shi)(shi)，應根據管(guan)(guan)(guan)(guan)(guan)(guan)子(zi)(zi)(zi)(zi)(zi)與(yu)管(guan)(guan)(guan)(guan)(guan)(guan)件(jian)(jian)(jian)等強度的(de)(de)原則以及(ji)管(guan)(guan)(guan)(guan)(guan)(guan)件(jian)(jian)(jian)與(yu)管(guan)(guan)(guan)(guan)(guan)(guan)子(zi)(zi)(zi)(zi)(zi)連接(jie)方式而(er)定。例如，當管(guan)(guan)(guan)(guan)(guan)(guan)子(zi)(zi)(zi)(zi)(zi)與(yu)管(guan)(guan)(guan)(guan)(guan)(guan)件(jian)(jian)(jian)采(cai)用(yong)對焊(han)(han)連接(jie)時(shi)(shi)，管(guan)(guan)(guan)(guan)(guan)(guan)子(zi)(zi)(zi)(zi)(zi)與(yu)不(bu)銹鋼管(guan)(guan)(guan)(guan)(guan)(guan)件(jian)(jian)(jian)的(de)(de)管(guan)(guan)(guan)(guan)(guan)(guan)子(zi)(zi)(zi)(zi)(zi)表(biao)(biao)號(hao)應一致(zhi)；而(er)當管(guan)(guan)(guan)(guan)(guan)(guan)子(zi)(zi)(zi)(zi)(zi)與(yu)管(guan)(guan)(guan)(guan)(guan)(guan)件(jian)(jian)(jian)采(cai)用(yong)承(cheng)插焊(han)(han)或螺(luo)紋連接(jie)時(shi)(shi)，標準(zhun)的(de)(de)承(cheng)插焊(han)(han)和螺(luo)紋管(guan)(guan)(guan)(guan)(guan)(guan)件(jian)(jian)(jian)的(de)(de)管(guan)(guan)(guan)(guan)(guan)(guan)子(zi)(zi)(zi)(zi)(zi)表(biao)(biao)號(hao)只有Sch80、Sch160、XXS三擋，最低的(de)(de)管(guan)(guan)(guan)(guan)(guan)(guan)子(zi)(zi)(zi)(zi)(zi)表(biao)(biao)號(hao)就(jiu)是(shi)Sch80，也就(jiu)是(shi)說只要當承(cheng)插焊(han)(han)或螺(luo)紋管(guan)(guan)(guan)(guan)(guan)(guan)件(jian)(jian)(jian)所(suo)連接(jie)的(de)(de)管(guan)(guan)(guan)(guan)(guan)(guan)子(zi)(zi)(zi)(zi)(zi)表(biao)(biao)號(hao)不(bu)大于Sch80時(shi)(shi)，承(cheng)插焊(han)(han)或螺(luo)紋管(guan)(guan)(guan)(guan)(guan)(guan)件(jian)(jian)(jian)的(de)(de)管(guan)(guan)(guan)(guan)(guan)(guan)子(zi)(zi)(zi)(zi)(zi)表(biao)(biao)號(hao)就(jiu)選Sch80，而(er)當所(suo)連接(jie)的(de)(de)管(guan)(guan)(guan)(guan)(guan)(guan)子(zi)(zi)(zi)(zi)(zi)表(biao)(biao)號(hao)大于Sch80時(shi)(shi)，承(cheng)插焊(han)(han)或螺(luo)紋管(guan)(guan)(guan)(guan)(guan)(guan)件(jian)(jian)(jian)的(de)(de)管(guan)(guan)(guan)(guan)(guan)(guan)子(zi)(zi)(zi)(zi)(zi)表(biao)(biao)號(hao)就(jiu)選Sch160或XXS。

   另(ling)外，當對(dui)焊三(san)通主(zhu)管(guan)(guan)(guan)、支(zhi)管(guan)(guan)(guan)所連接的(de)管(guan)(guan)(guan)子的(de)管(guan)(guan)(guan)子表(biao)號不同時，應注意(yi)三(san)通主(zhu)管(guan)(guan)(guan)、支(zhi)管(guan)(guan)(guan)端(duan)部的(de)管(guan)(guan)(guan)子表(biao)號應分別與其所連接的(de)管(guan)(guan)(guan)子的(de)管(guan)(guan)(guan)子表(biao)號相同，這樣就(jiu)非(fei)常(chang)方便(bian)管(guan)(guan)(guan)道(dao)施工，管(guan)(guan)(guan)件不必現場再打坡口。

   值得(de)注意的(de)是選用支管(guan)(guan)(guan)直接(jie)焊接(jie)在主管(guan)(guan)(guan)上這一種連接(jie)形式，要(yao)核算管(guan)(guan)(guan)子是否需要(yao)補強。支管(guan)(guan)(guan)補強的(de)方法在ASME B31.3、SH／T 3059《石油化工(gong)管(guan)(guan)(guan)道設計器材選用規(gui)范(fan)》、GB50316《工(gong)業金屬管(guan)(guan)(guan)道設計規(gui)范(fan)》、GB／T 20801《壓力管(guan)(guan)(guan)道規(gui)范(fan)工(gong)業管(guan)(guan)(guan)道》等標準規(gui)范(fan)中(zhong)均有詳細的(de)介紹。