1. 浙江至德鋼(gang)(gang)業有限(xian)公(gong)司發現有的(de)(de)(de)配管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)設計人員，經常混用(yong)(yong)英制管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)和(he)(he)公(gong)制管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)（注(zhu)意區(qu)分(fen)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)子(zi)公(gong)稱直徑(jing)(jing)(jing)(jing)(jing)是(shi)用(yong)(yong)英寸(cun)表示還(huan)是(shi)用(yong)(yong)毫米(mi)表示的(de)(de)(de)不同）。石油化(hua)工行(xing)業管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)子(zi)有公(gong)制和(he)(he)英制兩(liang)種(zhong)。公(gong)制鋼(gang)(gang)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)是(shi)按ISO4200《焊接和(he)(he)無(wu)縫(feng)平端鋼(gang)(gang)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)的(de)(de)(de)尺(chi)寸(cun)和(he)(he)單(dan)位(wei)長度重量(liang)一覽表》標準制造的(de)(de)(de)，而英制鋼(gang)(gang)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)則是(shi)按ASME B36.10《焊接和(he)(he)無(wu)縫(feng)軋制鋼(gang)(gang)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)》和(he)(he)ASME B36.19《不銹鋼(gang)(gang)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)》標準制造的(de)(de)(de)。過去，我國的(de)(de)(de)鋼(gang)(gang)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)規格分(fen)大(da)外(wai)(wai)(wai)(wai)徑(jing)(jing)(jing)(jing)(jing)系(xi)(xi)列(lie)(lie)和(he)(he)小(xiao)外(wai)(wai)(wai)(wai)徑(jing)(jing)(jing)(jing)(jing)系(xi)(xi)列(lie)(lie)兩(liang)種(zhong)，人們(men)把大(da)外(wai)(wai)(wai)(wai)徑(jing)(jing)(jing)(jing)(jing)系(xi)(xi)列(lie)(lie)稱為(wei)A系(xi)(xi)列(lie)(lie)，小(xiao)外(wai)(wai)(wai)(wai)徑(jing)(jing)(jing)(jing)(jing)系(xi)(xi)列(lie)(lie)稱為(wei)B系(xi)(xi)列(lie)(lie)。大(da)外(wai)(wai)(wai)(wai)徑(jing)(jing)(jing)(jing)(jing)系(xi)(xi)列(lie)(lie)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)子(zi)的(de)(de)(de)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)徑(jing)(jing)(jing)(jing)(jing)和(he)(he)ASME標準接近。小(xiao)外(wai)(wai)(wai)(wai)徑(jing)(jing)(jing)(jing)(jing)系(xi)(xi)列(lie)(lie)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)子(zi)的(de)(de)(de)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)徑(jing)(jing)(jing)(jing)(jing)和(he)(he)當時的(de)(de)(de)俄羅斯(si)標準一致。例(li)如，DN50mm的(de)(de)(de)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)子(zi)，大(da)外(wai)(wai)(wai)(wai)徑(jing)(jing)(jing)(jing)(jing)系(xi)(xi)列(lie)(lie)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)子(zi)的(de)(de)(de)外(wai)(wai)(wai)(wai)徑(jing)(jing)(jing)(jing)(jing)為(wei)60.3mm，而小(xiao)外(wai)(wai)(wai)(wai)徑(jing)(jing)(jing)(jing)(jing)系(xi)(xi)列(lie)(lie)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)子(zi)的(de)(de)(de)外(wai)(wai)(wai)(wai)徑(jing)(jing)(jing)(jing)(jing)為(wei)57mm；DN100mm的(de)(de)(de)大(da)外(wai)(wai)(wai)(wai)徑(jing)(jing)(jing)(jing)(jing)系(xi)(xi)列(lie)(lie)的(de)(de)(de)無(wu)縫(feng)鋼(gang)(gang)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)的(de)(de)(de)外(wai)(wai)(wai)(wai)徑(jing)(jing)(jing)(jing)(jing)為(wei)114mm，小(xiao)外(wai)(wai)(wai)(wai)徑(jing)(jing)(jing)(jing)(jing)系(xi)(xi)列(lie)(lie)的(de)(de)(de)無(wu)縫(feng)鋼(gang)(gang)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)的(de)(de)(de)外(wai)(wai)(wai)(wai)徑(jing)(jing)(jing)(jing)(jing)為(wei)108mm。現在，我國無(wu)縫(feng)鋼(gang)(gang)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)標準GB/T 17395《無(wu)縫(feng)鋼(gang)(gang)管(guan)(guan)(guan)(guan)(guan)(guan)(guan)(guan)尺(chi)寸(cun)、外(wai)(wai)(wai)(wai)形(xing)、重量(liang)及允許偏差》和(he)(he)ISO4200標準有一定的(de)(de)(de)對應性。

  2. 管子(zi)系(xi)列標準(zhun)，一類(lei)是以(yi)(yi)表4.1.6為對應外(wai)徑尺(chi)寸的所謂(wei)“大外(wai)徑”系(xi)列；另一類(lei)則是以(yi)(yi)表4.1.7為對應外(wai)徑尺(chi)寸的所謂(wei)“小外(wai)徑”系(xi)列。

       注：①. 在英(ying)制(zhi)單(dan)位轉化為公(gong)制(zhi)單(dan)位時約(yue)去了小數點。

             ②. 定義不確切，但已是多年來的習慣叫法(fa)，不妨仍(reng)這樣叫。“小(xiao)外徑”的概念也是如此。

  3. ISO4200標準(zhun)(zhun)把鋼(gang)管(guan)分成三個系(xi)列，三個系(xi)列的管(guan)外徑均不(bu)一(yi)(yi)樣。第一(yi)(yi)系(xi)列內的鋼(gang)管(guan)有標準(zhun)(zhun)化附(fu)件配用(yong)(yong)。第二系(xi)列則是沒有齊全(quan)的附(fu)件標準(zhun)(zhun)。第三系(xi)列是特殊用(yong)(yong)途鋼(gang)管(guan)，有很(hen)少(shao)量附(fu)件標準(zhun)(zhun)。ISO4200標準(zhun)(zhun)第一(yi)(yi)系(xi)列鋼(gang)管(guan)，其(qi)中有A～G7種優先(xian)選用(yong)(yong)壁(bi)厚(hou)，D、E、F和(he)(he)G壁(bi)厚(hou)常用(yong)(yong)于(yu)非合金和(he)(he)合金鋼(gang)材；A、B、C、E、F和(he)(he)G則常用(yong)(yong)于(yu)不(bu)銹鋼(gang)鋼(gang)管(guan)。GB／T17395標準(zhun)(zhun)則把鋼(gang)管(guan)分成通用(yong)(yong)、非通用(yong)(yong)和(he)(he)少(shao)數(shu)特殊、專用(yong)(yong)鋼(gang)管(guan)3個系(xi)列，3個系(xi)列的鋼(gang)管(guan)外徑均不(bu)相同。通用(yong)(yong)系(xi)列屬(shu)于(yu)推薦選用(yong)(yong)系(xi)列，管(guan)外徑和(he)(he)ISO4200標準(zhun)(zhun)第一(yi)(yi)系(xi)列一(yi)(yi)致(zhi)，但壁(bi)厚(hou)上限比ISO4200厚(hou)。英制管(guan)和(he)(he)公制管(guan)的特點(dian)，見表4.1.8。