①. 由于各國不(bu)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(zhi)(zhi)管連(lian)接件(jian)的(de)選(xuan)擇主要依(yi)據(ju)管道(dao)等級(ji)中已經(jing)確定的(de)法(fa)蘭壓(ya)力等級(ji)或公稱壓(ya)力來(lai)選(xuan)用支(zhi)(zhi)管連(lian)接件(jian)。

    一(yi)般情況下，當法蘭的公(gong)(gong)稱(cheng)(cheng)壓力(li)不大于(yu)PN2.5（Class 150）時(shi)，支(zhi)管直接焊(han)接在主(zhu)管上；當公(gong)(gong)稱(cheng)(cheng)壓力(li)不小于(yu)PN4.0（Class 300）時(shi)，則根據(ju)主(zhu)管、支(zhi)管公(gong)(gong)稱(cheng)(cheng)直徑的不同按(an)對焊(han)三通、焊(han)接支(zhi)管臺、承插焊(han)或(huo)螺紋連接三通、承插焊(han)或(huo)螺紋支(zhi)管臺的順序選用。

  ③. 支管連接件(jian)的(de)管子表號。

   值得(de)注(zhu)意的是在確定支管(guan)(guan)(guan)連接(jie)件(jian)(jian)的管(guan)(guan)(guan)子(zi)(zi)表(biao)號時(shi)(shi)，應根據管(guan)(guan)(guan)子(zi)(zi)與管(guan)(guan)(guan)件(jian)(jian)等強度(du)的原(yuan)則以及管(guan)(guan)(guan)件(jian)(jian)與管(guan)(guan)(guan)子(zi)(zi)連接(jie)方式而(er)定。例如，當管(guan)(guan)(guan)子(zi)(zi)與管(guan)(guan)(guan)件(jian)(jian)采用對焊連接(jie)時(shi)(shi)，管(guan)(guan)(guan)子(zi)(zi)與不銹鋼管(guan)(guan)(guan)件(jian)(jian)的管(guan)(guan)(guan)子(zi)(zi)表(biao)號應一致；而(er)當管(guan)(guan)(guan)子(zi)(zi)與管(guan)(guan)(guan)件(jian)(jian)采用承(cheng)插(cha)焊或(huo)螺(luo)(luo)紋(wen)(wen)連接(jie)時(shi)(shi)，標準的承(cheng)插(cha)焊和(he)螺(luo)(luo)紋(wen)(wen)管(guan)(guan)(guan)件(jian)(jian)的管(guan)(guan)(guan)子(zi)(zi)表(biao)號只有Sch80、Sch160、XXS三擋，最低的管(guan)(guan)(guan)子(zi)(zi)表(biao)號就(jiu)是Sch80，也就(jiu)是說只要(yao)當承(cheng)插(cha)焊或(huo)螺(luo)(luo)紋(wen)(wen)管(guan)(guan)(guan)件(jian)(jian)所連接(jie)的管(guan)(guan)(guan)子(zi)(zi)表(biao)號不大于(yu)Sch80時(shi)(shi)，承(cheng)插(cha)焊或(huo)螺(luo)(luo)紋(wen)(wen)管(guan)(guan)(guan)件(jian)(jian)的管(guan)(guan)(guan)子(zi)(zi)表(biao)號就(jiu)選(xuan)Sch80，而(er)當所連接(jie)的管(guan)(guan)(guan)子(zi)(zi)表(biao)號大于(yu)Sch80時(shi)(shi)，承(cheng)插(cha)焊或(huo)螺(luo)(luo)紋(wen)(wen)管(guan)(guan)(guan)件(jian)(jian)的管(guan)(guan)(guan)子(zi)(zi)表(biao)號就(jiu)選(xuan)Sch160或(huo)XXS。

   另外，當對焊(han)三通(tong)主(zhu)管、支(zhi)管所(suo)連接(jie)的(de)管子的(de)管子表(biao)號不(bu)同(tong)時，應(ying)注意(yi)三通(tong)主(zhu)管、支(zhi)管端部的(de)管子表(biao)號應(ying)分別與其所(suo)連接(jie)的(de)管子的(de)管子表(biao)號相同(tong)，這樣就非常方便(bian)管道(dao)施工，管件(jian)不(bu)必現場再打坡口(kou)。

   值得注意的是(shi)選用(yong)支管(guan)(guan)(guan)直接(jie)焊接(jie)在主管(guan)(guan)(guan)上這(zhe)一種連(lian)接(jie)形(xing)式，要(yao)核算管(guan)(guan)(guan)子是(shi)否需要(yao)補強。支管(guan)(guan)(guan)補強的方法(fa)在ASME B31.3、SH／T 3059《石(shi)油化工(gong)管(guan)(guan)(guan)道(dao)設計器材選用(yong)規(gui)范(fan)(fan)》、GB50316《工(gong)業金(jin)屬管(guan)(guan)(guan)道(dao)設計規(gui)范(fan)(fan)》、GB／T 20801《壓力(li)管(guan)(guan)(guan)道(dao)規(gui)范(fan)(fan)工(gong)業管(guan)(guan)(guan)道(dao)》等標準規(gui)范(fan)(fan)中均(jun)有詳細的介紹。