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. 支管連(lian)接件的選擇主要依據(ju)管道等級中已經確定(ding)的法(fa)蘭壓力(li)等級或(huo)公稱壓力(li)來(lai)選用支管連(lian)接件。
一般情況下,當法蘭的公(gong)(gong)稱(cheng)壓力(li)不大于(yu)PN2.5(Class 150)時,支(zhi)(zhi)管(guan)直接(jie)(jie)焊(han)(han)(han)接(jie)(jie)在主管(guan)上;當公(gong)(gong)稱(cheng)壓力(li)不小于(yu)PN4.0(Class 300)時,則根據主管(guan)、支(zhi)(zhi)管(guan)公(gong)(gong)稱(cheng)直徑(jing)的不同按對焊(han)(han)(han)三通(tong)、焊(han)(han)(han)接(jie)(jie)支(zhi)(zhi)管(guan)臺(tai)、承插(cha)焊(han)(han)(han)或螺紋連接(jie)(jie)三通(tong)、承插(cha)焊(han)(han)(han)或螺紋支(zhi)(zhi)管(guan)臺(tai)的順序(xu)選(xuan)用(yong)。
③. 支管連(lian)接(jie)件的(de)管子表號。
值得注意的(de)(de)(de)(de)是(shi)在確(que)定支管(guan)(guan)(guan)(guan)連(lian)(lian)(lian)接(jie)(jie)(jie)件(jian)的(de)(de)(de)(de)管(guan)(guan)(guan)(guan)子(zi)(zi)(zi)表號(hao)(hao)時(shi),應根據管(guan)(guan)(guan)(guan)子(zi)(zi)(zi)與(yu)管(guan)(guan)(guan)(guan)件(jian)等強度的(de)(de)(de)(de)原則以及管(guan)(guan)(guan)(guan)件(jian)與(yu)管(guan)(guan)(guan)(guan)子(zi)(zi)(zi)連(lian)(lian)(lian)接(jie)(jie)(jie)方式而定。例如,當(dang)管(guan)(guan)(guan)(guan)子(zi)(zi)(zi)與(yu)管(guan)(guan)(guan)(guan)件(jian)采用對焊(han)連(lian)(lian)(lian)接(jie)(jie)(jie)時(shi),管(guan)(guan)(guan)(guan)子(zi)(zi)(zi)與(yu)不(bu)銹鋼(gang)管(guan)(guan)(guan)(guan)件(jian)的(de)(de)(de)(de)管(guan)(guan)(guan)(guan)子(zi)(zi)(zi)表號(hao)(hao)應一(yi)致(zhi);而當(dang)管(guan)(guan)(guan)(guan)子(zi)(zi)(zi)與(yu)管(guan)(guan)(guan)(guan)件(jian)采用承插(cha)(cha)焊(han)或(huo)(huo)螺(luo)紋(wen)(wen)連(lian)(lian)(lian)接(jie)(jie)(jie)時(shi),標準的(de)(de)(de)(de)承插(cha)(cha)焊(han)和螺(luo)紋(wen)(wen)管(guan)(guan)(guan)(guan)件(jian)的(de)(de)(de)(de)管(guan)(guan)(guan)(guan)子(zi)(zi)(zi)表號(hao)(hao)只有Sch80、Sch160、XXS三擋,最低的(de)(de)(de)(de)管(guan)(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(yao)當(dang)承插(cha)(cha)焊(han)或(huo)(huo)螺(luo)紋(wen)(wen)管(guan)(guan)(guan)(guan)件(jian)所連(lian)(lian)(lian)接(jie)(jie)(jie)的(de)(de)(de)(de)管(guan)(guan)(guan)(guan)子(zi)(zi)(zi)表號(hao)(hao)不(bu)大于(yu)Sch80時(shi),承插(cha)(cha)焊(han)或(huo)(huo)螺(luo)紋(wen)(wen)管(guan)(guan)(guan)(guan)件(jian)的(de)(de)(de)(de)管(guan)(guan)(guan)(guan)子(zi)(zi)(zi)表號(hao)(hao)就(jiu)選(xuan)Sch80,而當(dang)所連(lian)(lian)(lian)接(jie)(jie)(jie)的(de)(de)(de)(de)管(guan)(guan)(guan)(guan)子(zi)(zi)(zi)表號(hao)(hao)大于(yu)Sch80時(shi),承插(cha)(cha)焊(han)或(huo)(huo)螺(luo)紋(wen)(wen)管(guan)(guan)(guan)(guan)件(jian)的(de)(de)(de)(de)管(guan)(guan)(guan)(guan)子(zi)(zi)(zi)表號(hao)(hao)就(jiu)選(xuan)Sch160或(huo)(huo)XXS。
另外,當(dang)對焊三(san)通主管(guan)(guan)(guan)(guan)、支管(guan)(guan)(guan)(guan)所連接的(de)管(guan)(guan)(guan)(guan)子(zi)(zi)的(de)管(guan)(guan)(guan)(guan)子(zi)(zi)表(biao)號不同(tong)時,應注意(yi)三(san)通主管(guan)(guan)(guan)(guan)、支管(guan)(guan)(guan)(guan)端部的(de)管(guan)(guan)(guan)(guan)子(zi)(zi)表(biao)號應分(fen)別與其所連接的(de)管(guan)(guan)(guan)(guan)子(zi)(zi)的(de)管(guan)(guan)(guan)(guan)子(zi)(zi)表(biao)號相同(tong),這樣就(jiu)非常(chang)方便管(guan)(guan)(guan)(guan)道施工,管(guan)(guan)(guan)(guan)件不必現場再打(da)坡口。
值得注意(yi)的是選(xuan)用(yong)(yong)支管(guan)直接(jie)(jie)焊接(jie)(jie)在(zai)主管(guan)上這一種連接(jie)(jie)形(xing)式,要核算管(guan)子是否需要補強。支管(guan)補強的方(fang)法在(zai)ASME B31.3、SH/T 3059《石油(you)化工管(guan)道(dao)設(she)(she)計器材選(xuan)用(yong)(yong)規(gui)范》、GB50316《工業金屬管(guan)道(dao)設(she)(she)計規(gui)范》、GB/T 20801《壓力管(guan)道(dao)規(gui)范工業管(guan)道(dao)》等(deng)標(biao)準規(gui)范中(zhong)均有詳(xiang)細(xi)的介紹。