1. 浙江至德鋼業有(you)限公司發現有(you)的(de)(de)(de)(de)配管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)設計人員，經常混(hun)用(yong)(yong)英(ying)制(zhi)(zhi)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)和(he)(he)公制(zhi)(zhi)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)（注意區分管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)子(zi)公稱(cheng)直徑(jing)(jing)(jing)是(shi)用(yong)(yong)英(ying)寸表示(shi)還是(shi)用(yong)(yong)毫米表示(shi)的(de)(de)(de)(de)不同）。石油化工行(xing)業管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)子(zi)有(you)公制(zhi)(zhi)和(he)(he)英(ying)制(zhi)(zhi)兩(liang)種。公制(zhi)(zhi)鋼管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)是(shi)按ISO4200《焊接(jie)和(he)(he)無縫(feng)(feng)平(ping)端鋼管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)的(de)(de)(de)(de)尺寸和(he)(he)單(dan)位長度重量(liang)一覽(lan)表》標(biao)(biao)準(zhun)制(zhi)(zhi)造的(de)(de)(de)(de)，而(er)英(ying)制(zhi)(zhi)鋼管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)則(ze)是(shi)按ASME B36.10《焊接(jie)和(he)(he)無縫(feng)(feng)軋制(zhi)(zhi)鋼管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)》和(he)(he)ASME B36.19《不銹鋼管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)》標(biao)(biao)準(zhun)制(zhi)(zhi)造的(de)(de)(de)(de)。過去，我(wo)國(guo)的(de)(de)(de)(de)鋼管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)規格(ge)分大外(wai)(wai)(wai)(wai)(wai)徑(jing)(jing)(jing)系(xi)(xi)(xi)(xi)(xi)列(lie)(lie)(lie)和(he)(he)小外(wai)(wai)(wai)(wai)(wai)徑(jing)(jing)(jing)系(xi)(xi)(xi)(xi)(xi)列(lie)(lie)(lie)兩(liang)種，人們(men)把大外(wai)(wai)(wai)(wai)(wai)徑(jing)(jing)(jing)系(xi)(xi)(xi)(xi)(xi)列(lie)(lie)(lie)稱(cheng)為(wei)(wei)A系(xi)(xi)(xi)(xi)(xi)列(lie)(lie)(lie)，小外(wai)(wai)(wai)(wai)(wai)徑(jing)(jing)(jing)系(xi)(xi)(xi)(xi)(xi)列(lie)(lie)(lie)稱(cheng)為(wei)(wei)B系(xi)(xi)(xi)(xi)(xi)列(lie)(lie)(lie)。大外(wai)(wai)(wai)(wai)(wai)徑(jing)(jing)(jing)系(xi)(xi)(xi)(xi)(xi)列(lie)(lie)(lie)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)子(zi)的(de)(de)(de)(de)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)徑(jing)(jing)(jing)和(he)(he)ASME標(biao)(biao)準(zhun)接(jie)近。小外(wai)(wai)(wai)(wai)(wai)徑(jing)(jing)(jing)系(xi)(xi)(xi)(xi)(xi)列(lie)(lie)(lie)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)子(zi)的(de)(de)(de)(de)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)徑(jing)(jing)(jing)和(he)(he)當時的(de)(de)(de)(de)俄羅斯標(biao)(biao)準(zhun)一致。例如，DN50mm的(de)(de)(de)(de)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)子(zi)，大外(wai)(wai)(wai)(wai)(wai)徑(jing)(jing)(jing)系(xi)(xi)(xi)(xi)(xi)列(lie)(lie)(lie)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)子(zi)的(de)(de)(de)(de)外(wai)(wai)(wai)(wai)(wai)徑(jing)(jing)(jing)為(wei)(wei)60.3mm，而(er)小外(wai)(wai)(wai)(wai)(wai)徑(jing)(jing)(jing)系(xi)(xi)(xi)(xi)(xi)列(lie)(lie)(lie)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)子(zi)的(de)(de)(de)(de)外(wai)(wai)(wai)(wai)(wai)徑(jing)(jing)(jing)為(wei)(wei)57mm；DN100mm的(de)(de)(de)(de)大外(wai)(wai)(wai)(wai)(wai)徑(jing)(jing)(jing)系(xi)(xi)(xi)(xi)(xi)列(lie)(lie)(lie)的(de)(de)(de)(de)無縫(feng)(feng)鋼管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)的(de)(de)(de)(de)外(wai)(wai)(wai)(wai)(wai)徑(jing)(jing)(jing)為(wei)(wei)114mm，小外(wai)(wai)(wai)(wai)(wai)徑(jing)(jing)(jing)系(xi)(xi)(xi)(xi)(xi)列(lie)(lie)(lie)的(de)(de)(de)(de)無縫(feng)(feng)鋼管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)的(de)(de)(de)(de)外(wai)(wai)(wai)(wai)(wai)徑(jing)(jing)(jing)為(wei)(wei)108mm。現在(zai)，我(wo)國(guo)無縫(feng)(feng)鋼管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)標(biao)(biao)準(zhun)GB/T 17395《無縫(feng)(feng)鋼管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)尺寸、外(wai)(wai)(wai)(wai)(wai)形、重量(liang)及(ji)允許偏差》和(he)(he)ISO4200標(biao)(biao)準(zhun)有(you)一定(ding)的(de)(de)(de)(de)對應性。

  2. 管子系列標準，一(yi)類(lei)是以表(biao)4.1.6為對應(ying)外(wai)徑(jing)尺(chi)寸的所(suo)謂(wei)“大外(wai)徑(jing)”系列；另一(yi)類(lei)則是以表(biao)4.1.7為對應(ying)外(wai)徑(jing)尺(chi)寸的所(suo)謂(wei)“小外(wai)徑(jing)”系列。

       注：①. 在英(ying)制單位(wei)轉化為公制單位(wei)時約去(qu)了小(xiao)數點。

             ②. 定義不確切，但已是多年(nian)來的習(xi)慣叫法，不妨仍這樣叫。“小外徑”的概念也(ye)是如此。

  3. ISO4200標(biao)(biao)(biao)準(zhun)(zhun)(zhun)把鋼(gang)管(guan)分成三(san)個(ge)(ge)系(xi)(xi)(xi)(xi)列(lie)，三(san)個(ge)(ge)系(xi)(xi)(xi)(xi)列(lie)的(de)管(guan)外(wai)(wai)徑均(jun)不一樣(yang)。第一系(xi)(xi)(xi)(xi)列(lie)內(nei)的(de)鋼(gang)管(guan)有(you)標(biao)(biao)(biao)準(zhun)(zhun)(zhun)化附件(jian)配(pei)用(yong)(yong)(yong)。第二系(xi)(xi)(xi)(xi)列(lie)則是沒(mei)有(you)齊全的(de)附件(jian)標(biao)(biao)(biao)準(zhun)(zhun)(zhun)。第三(san)系(xi)(xi)(xi)(xi)列(lie)是特(te)殊用(yong)(yong)(yong)途鋼(gang)管(guan)，有(you)很少量附件(jian)標(biao)(biao)(biao)準(zhun)(zhun)(zhun)。ISO4200標(biao)(biao)(biao)準(zhun)(zhun)(zhun)第一系(xi)(xi)(xi)(xi)列(lie)鋼(gang)管(guan)，其(qi)中有(you)A～G7種(zhong)優先選用(yong)(yong)(yong)壁(bi)厚，D、E、F和(he)(he)G壁(bi)厚常用(yong)(yong)(yong)于(yu)非(fei)合金和(he)(he)合金鋼(gang)材；A、B、C、E、F和(he)(he)G則常用(yong)(yong)(yong)于(yu)不銹鋼(gang)鋼(gang)管(guan)。GB／T17395標(biao)(biao)(biao)準(zhun)(zhun)(zhun)則把鋼(gang)管(guan)分成通用(yong)(yong)(yong)、非(fei)通用(yong)(yong)(yong)和(he)(he)少數特(te)殊、專用(yong)(yong)(yong)鋼(gang)管(guan)3個(ge)(ge)系(xi)(xi)(xi)(xi)列(lie)，3個(ge)(ge)系(xi)(xi)(xi)(xi)列(lie)的(de)鋼(gang)管(guan)外(wai)(wai)徑均(jun)不相同。通用(yong)(yong)(yong)系(xi)(xi)(xi)(xi)列(lie)屬于(yu)推薦(jian)選用(yong)(yong)(yong)系(xi)(xi)(xi)(xi)列(lie)，管(guan)外(wai)(wai)徑和(he)(he)ISO4200標(biao)(biao)(biao)準(zhun)(zhun)(zhun)第一系(xi)(xi)(xi)(xi)列(lie)一致，但壁(bi)厚上限(xian)比ISO4200厚。英制(zhi)管(guan)和(he)(he)公制(zhi)管(guan)的(de)特(te)點，見表4.1.8。