1. 浙江(jiang)至德鋼(gang)(gang)(gang)業有(you)(you)限(xian)公(gong)司發(fa)現有(you)(you)的(de)(de)配管(guan)(guan)(guan)(guan)(guan)(guan)設計人(ren)員，經(jing)常混(hun)用(yong)(yong)英(ying)(ying)制(zhi)管(guan)(guan)(guan)(guan)(guan)(guan)和(he)(he)公(gong)制(zhi)管(guan)(guan)(guan)(guan)(guan)(guan)（注意(yi)區分管(guan)(guan)(guan)(guan)(guan)(guan)子公(gong)稱(cheng)直徑(jing)(jing)(jing)(jing)(jing)(jing)是(shi)用(yong)(yong)英(ying)(ying)寸(cun)表(biao)示還是(shi)用(yong)(yong)毫(hao)米表(biao)示的(de)(de)不同）。石油化(hua)工行業管(guan)(guan)(guan)(guan)(guan)(guan)子有(you)(you)公(gong)制(zhi)和(he)(he)英(ying)(ying)制(zhi)兩(liang)種。公(gong)制(zhi)鋼(gang)(gang)(gang)管(guan)(guan)(guan)(guan)(guan)(guan)是(shi)按ISO4200《焊接(jie)和(he)(he)無(wu)縫(feng)平(ping)端鋼(gang)(gang)(gang)管(guan)(guan)(guan)(guan)(guan)(guan)管(guan)(guan)(guan)(guan)(guan)(guan)的(de)(de)尺寸(cun)和(he)(he)單位長度重(zhong)(zhong)量(liang)一(yi)覽表(biao)》標(biao)(biao)準制(zhi)造的(de)(de)，而英(ying)(ying)制(zhi)鋼(gang)(gang)(gang)管(guan)(guan)(guan)(guan)(guan)(guan)則(ze)是(shi)按ASME B36.10《焊接(jie)和(he)(he)無(wu)縫(feng)軋(ya)制(zhi)鋼(gang)(gang)(gang)管(guan)(guan)(guan)(guan)(guan)(guan)》和(he)(he)ASME B36.19《不銹鋼(gang)(gang)(gang)管(guan)(guan)(guan)(guan)(guan)(guan)》標(biao)(biao)準制(zhi)造的(de)(de)。過去，我(wo)(wo)國的(de)(de)鋼(gang)(gang)(gang)管(guan)(guan)(guan)(guan)(guan)(guan)規格(ge)分大(da)(da)外(wai)(wai)徑(jing)(jing)(jing)(jing)(jing)(jing)系列(lie)(lie)和(he)(he)小(xiao)(xiao)外(wai)(wai)徑(jing)(jing)(jing)(jing)(jing)(jing)系列(lie)(lie)兩(liang)種，人(ren)們把大(da)(da)外(wai)(wai)徑(jing)(jing)(jing)(jing)(jing)(jing)系列(lie)(lie)稱(cheng)為(wei)A系列(lie)(lie)，小(xiao)(xiao)外(wai)(wai)徑(jing)(jing)(jing)(jing)(jing)(jing)系列(lie)(lie)稱(cheng)為(wei)B系列(lie)(lie)。大(da)(da)外(wai)(wai)徑(jing)(jing)(jing)(jing)(jing)(jing)系列(lie)(lie)管(guan)(guan)(guan)(guan)(guan)(guan)子的(de)(de)管(guan)(guan)(guan)(guan)(guan)(guan)徑(jing)(jing)(jing)(jing)(jing)(jing)和(he)(he)ASME標(biao)(biao)準接(jie)近。小(xiao)(xiao)外(wai)(wai)徑(jing)(jing)(jing)(jing)(jing)(jing)系列(lie)(lie)管(guan)(guan)(guan)(guan)(guan)(guan)子的(de)(de)管(guan)(guan)(guan)(guan)(guan)(guan)徑(jing)(jing)(jing)(jing)(jing)(jing)和(he)(he)當時的(de)(de)俄羅斯標(biao)(biao)準一(yi)致。例如，DN50mm的(de)(de)管(guan)(guan)(guan)(guan)(guan)(guan)子，大(da)(da)外(wai)(wai)徑(jing)(jing)(jing)(jing)(jing)(jing)系列(lie)(lie)管(guan)(guan)(guan)(guan)(guan)(guan)子的(de)(de)外(wai)(wai)徑(jing)(jing)(jing)(jing)(jing)(jing)為(wei)60.3mm，而小(xiao)(xiao)外(wai)(wai)徑(jing)(jing)(jing)(jing)(jing)(jing)系列(lie)(lie)管(guan)(guan)(guan)(guan)(guan)(guan)子的(de)(de)外(wai)(wai)徑(jing)(jing)(jing)(jing)(jing)(jing)為(wei)57mm；DN100mm的(de)(de)大(da)(da)外(wai)(wai)徑(jing)(jing)(jing)(jing)(jing)(jing)系列(lie)(lie)的(de)(de)無(wu)縫(feng)鋼(gang)(gang)(gang)管(guan)(guan)(guan)(guan)(guan)(guan)的(de)(de)外(wai)(wai)徑(jing)(jing)(jing)(jing)(jing)(jing)為(wei)114mm，小(xiao)(xiao)外(wai)(wai)徑(jing)(jing)(jing)(jing)(jing)(jing)系列(lie)(lie)的(de)(de)無(wu)縫(feng)鋼(gang)(gang)(gang)管(guan)(guan)(guan)(guan)(guan)(guan)的(de)(de)外(wai)(wai)徑(jing)(jing)(jing)(jing)(jing)(jing)為(wei)108mm。現在，我(wo)(wo)國無(wu)縫(feng)鋼(gang)(gang)(gang)管(guan)(guan)(guan)(guan)(guan)(guan)標(biao)(biao)準GB/T 17395《無(wu)縫(feng)鋼(gang)(gang)(gang)管(guan)(guan)(guan)(guan)(guan)(guan)尺寸(cun)、外(wai)(wai)形、重(zhong)(zhong)量(liang)及允許偏(pian)差》和(he)(he)ISO4200標(biao)(biao)準有(you)(you)一(yi)定的(de)(de)對(dui)應性(xing)。
2. 管子系(xi)列標準(zhun)，一(yi)類是以表4.1.6為(wei)對(dui)應外(wai)(wai)(wai)(wai)徑(jing)(jing)尺寸的所謂“大外(wai)(wai)(wai)(wai)徑(jing)(jing)”系(xi)列；另一(yi)類則是以表4.1.7為(wei)對(dui)應外(wai)(wai)(wai)(wai)徑(jing)(jing)尺寸的所謂“小外(wai)(wai)(wai)(wai)徑(jing)(jing)”系(xi)列。
注：①. 在(zai)英制單(dan)位(wei)轉化(hua)為公制單(dan)位(wei)時約去了小數點。
②. 定義不確切，但已(yi)是多年來的習慣叫(jiao)法，不妨仍這樣叫(jiao)。“小外(wai)徑”的概念也是如(ru)此。
3. ISO4200標(biao)(biao)(biao)準(zhun)(zhun)(zhun)把鋼(gang)管(guan)(guan)(guan)分成三(san)(san)(san)個系(xi)列(lie)(lie)，三(san)(san)(san)個系(xi)列(lie)(lie)的(de)(de)(de)(de)管(guan)(guan)(guan)外(wai)(wai)徑均(jun)不一(yi)(yi)樣。第一(yi)(yi)系(xi)列(lie)(lie)內的(de)(de)(de)(de)鋼(gang)管(guan)(guan)(guan)有(you)(you)標(biao)(biao)(biao)準(zhun)(zhun)(zhun)化附件配用(yong)(yong)(yong)(yong)。第二系(xi)列(lie)(lie)則(ze)是沒(mei)有(you)(you)齊全(quan)的(de)(de)(de)(de)附件標(biao)(biao)(biao)準(zhun)(zhun)(zhun)。第三(san)(san)(san)系(xi)列(lie)(lie)是特(te)殊(shu)(shu)用(yong)(yong)(yong)(yong)途鋼(gang)管(guan)(guan)(guan)，有(you)(you)很少量(liang)附件標(biao)(biao)(biao)準(zhun)(zhun)(zhun)。ISO4200標(biao)(biao)(biao)準(zhun)(zhun)(zhun)第一(yi)(yi)系(xi)列(lie)(lie)鋼(gang)管(guan)(guan)(guan)，其中(zhong)有(you)(you)A～G7種優先選(xuan)用(yong)(yong)(yong)(yong)壁厚，D、E、F和G壁厚常用(yong)(yong)(yong)(yong)于(yu)非合(he)金(jin)和合(he)金(jin)鋼(gang)材；A、B、C、E、F和G則(ze)常用(yong)(yong)(yong)(yong)于(yu)不銹鋼(gang)鋼(gang)管(guan)(guan)(guan)。GB／T17395標(biao)(biao)(biao)準(zhun)(zhun)(zhun)則(ze)把鋼(gang)管(guan)(guan)(guan)分成通用(yong)(yong)(yong)(yong)、非通用(yong)(yong)(yong)(yong)和少數特(te)殊(shu)(shu)、專(zhuan)用(yong)(yong)(yong)(yong)鋼(gang)管(guan)(guan)(guan)3個系(xi)列(lie)(lie)，3個系(xi)列(lie)(lie)的(de)(de)(de)(de)鋼(gang)管(guan)(guan)(guan)外(wai)(wai)徑均(jun)不相同。通用(yong)(yong)(yong)(yong)系(xi)列(lie)(lie)屬于(yu)推薦選(xuan)用(yong)(yong)(yong)(yong)系(xi)列(lie)(lie)，管(guan)(guan)(guan)外(wai)(wai)徑和ISO4200標(biao)(biao)(biao)準(zhun)(zhun)(zhun)第一(yi)(yi)系(xi)列(lie)(lie)一(yi)(yi)致(zhi)，但壁厚上限比ISO4200厚。英制(zhi)管(guan)(guan)(guan)和公制(zhi)管(guan)(guan)(guan)的(de)(de)(de)(de)特(te)點，見表4.1.8。
