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(xuan)擇主要依(yi)據管道等(deng)級中(zhong)已經(jing)確定的法蘭壓力(li)等(deng)級或公稱壓力(li)來選(xuan)用(yong)支管連(lian)接件。
一般情況下(xia),當法蘭的(de)公(gong)稱(cheng)壓(ya)力不大于PN2.5(Class 150)時,支(zhi)管直(zhi)接焊(han)(han)接在主管上(shang);當公(gong)稱(cheng)壓(ya)力不小(xiao)于PN4.0(Class 300)時,則根據主管、支(zhi)管公(gong)稱(cheng)直(zhi)徑(jing)的(de)不同按對焊(han)(han)三通、焊(han)(han)接支(zhi)管臺(tai)、承插焊(han)(han)或(huo)螺紋(wen)連接三通、承插焊(han)(han)或(huo)螺紋(wen)支(zhi)管臺(tai)的(de)順序選用。
③. 支管連接件的管子表號。
值得注意的(de)(de)(de)(de)是在確定支管(guan)(guan)(guan)(guan)(guan)(guan)連接(jie)件(jian)(jian)(jian)(jian)(jian)的(de)(de)(de)(de)管(guan)(guan)(guan)(guan)(guan)(guan)子(zi)(zi)(zi)(zi)(zi)表(biao)(biao)號(hao)(hao)(hao)時,應根(gen)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)(jian)(jian)等強(qiang)度的(de)(de)(de)(de)原則(ze)以(yi)及管(guan)(guan)(guan)(guan)(guan)(guan)件(jian)(jian)(jian)(jian)(jian)與(yu)管(guan)(guan)(guan)(guan)(guan)(guan)子(zi)(zi)(zi)(zi)(zi)連接(jie)方式而定。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)(jian)(jian)采用對焊連接(jie)時,管(guan)(guan)(guan)(guan)(guan)(guan)子(zi)(zi)(zi)(zi)(zi)與(yu)不銹鋼(gang)管(guan)(guan)(guan)(guan)(guan)(guan)件(jian)(jian)(jian)(jian)(jian)的(de)(de)(de)(de)管(guan)(guan)(guan)(guan)(guan)(guan)子(zi)(zi)(zi)(zi)(zi)表(biao)(biao)號(hao)(hao)(hao)應一致;而當管(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)(jian)(jian)采用承(cheng)(cheng)插焊或螺紋(wen)連接(jie)時,標準(zhun)的(de)(de)(de)(de)承(cheng)(cheng)插焊和螺紋(wen)管(guan)(guan)(guan)(guan)(guan)(guan)件(jian)(jian)(jian)(jian)(jian)的(de)(de)(de)(de)管(guan)(guan)(guan)(guan)(guan)(guan)子(zi)(zi)(zi)(zi)(zi)表(biao)(biao)號(hao)(hao)(hao)只有Sch80、Sch160、XXS三擋,最低(di)的(de)(de)(de)(de)管(guan)(guan)(guan)(guan)(guan)(guan)子(zi)(zi)(zi)(zi)(zi)表(biao)(biao)號(hao)(hao)(hao)就(jiu)(jiu)是Sch80,也就(jiu)(jiu)是說只要當承(cheng)(cheng)插焊或螺紋(wen)管(guan)(guan)(guan)(guan)(guan)(guan)件(jian)(jian)(jian)(jian)(jian)所(suo)連接(jie)的(de)(de)(de)(de)管(guan)(guan)(guan)(guan)(guan)(guan)子(zi)(zi)(zi)(zi)(zi)表(biao)(biao)號(hao)(hao)(hao)不大(da)于Sch80時,承(cheng)(cheng)插焊或螺紋(wen)管(guan)(guan)(guan)(guan)(guan)(guan)件(jian)(jian)(jian)(jian)(jian)的(de)(de)(de)(de)管(guan)(guan)(guan)(guan)(guan)(guan)子(zi)(zi)(zi)(zi)(zi)表(biao)(biao)號(hao)(hao)(hao)就(jiu)(jiu)選Sch80,而當所(suo)連接(jie)的(de)(de)(de)(de)管(guan)(guan)(guan)(guan)(guan)(guan)子(zi)(zi)(zi)(zi)(zi)表(biao)(biao)號(hao)(hao)(hao)大(da)于Sch80時,承(cheng)(cheng)插焊或螺紋(wen)管(guan)(guan)(guan)(guan)(guan)(guan)件(jian)(jian)(jian)(jian)(jian)的(de)(de)(de)(de)管(guan)(guan)(guan)(guan)(guan)(guan)子(zi)(zi)(zi)(zi)(zi)表(biao)(biao)號(hao)(hao)(hao)就(jiu)(jiu)選Sch160或XXS。
另(ling)外,當對焊三(san)通主管(guan)、支(zhi)管(guan)所(suo)連接(jie)的(de)管(guan)子(zi)的(de)管(guan)子(zi)表(biao)號(hao)不(bu)(bu)同(tong)時,應注意三(san)通主管(guan)、支(zhi)管(guan)端部的(de)管(guan)子(zi)表(biao)號(hao)應分別與其所(suo)連接(jie)的(de)管(guan)子(zi)的(de)管(guan)子(zi)表(biao)號(hao)相同(tong),這樣就非常方(fang)便管(guan)道施工,管(guan)件不(bu)(bu)必現場再打坡口。
值得注意的是選用支管(guan)(guan)(guan)直接(jie)焊(han)接(jie)在(zai)主管(guan)(guan)(guan)上這一種連(lian)接(jie)形式(shi),要核算管(guan)(guan)(guan)子是否需要補強。支管(guan)(guan)(guan)補強的方法在(zai)ASME B31.3、SH/T 3059《石油化工管(guan)(guan)(guan)道(dao)(dao)設(she)計器(qi)材(cai)選用規范(fan)》、GB50316《工業金屬(shu)管(guan)(guan)(guan)道(dao)(dao)設(she)計規范(fan)》、GB/T 20801《壓力管(guan)(guan)(guan)道(dao)(dao)規范(fan)工業管(guan)(guan)(guan)道(dao)(dao)》等標準規范(fan)中(zhong)均有詳細的介(jie)紹(shao)。