常有(you)(you)(you)管(guan)(guan)(guan)道(dao)設計人員(yuan)向筆者咨(zi)詢Pipe與Tube管(guan)(guan)(guan)道(dao)的(de)(de)(de)區別。在(zai)ASME B31.1（動(dong)力管(guan)(guan)(guan)道(dao)）第(di)100.2節中有(you)(you)(you)詳細的(de)(de)(de)定(ding)義(yi)。Pipe是(shi)(shi)(shi)有(you)(you)(you)圓形(xing)(xing)截面的(de)(de)(de)空心制(zhi)品；Tube是(shi)(shi)(shi)具有(you)(you)(you)連(lian)續(xu)周圓形(xing)(xing)或任何其截面形(xing)(xing)狀的(de)(de)(de)空心制(zhi)品。在(zai)規(gui)(gui)格(ge)(ge)表(biao)(biao)(biao)示(shi)上，Tube的(de)(de)(de)外(wai)徑、內徑和(he)壁(bi)厚可(ke)用兩(liang)個獨立(li)參數表(biao)(biao)(biao)示(shi)，即國內常用的(de)(de)(de)外(wai)徑x壁(bi)厚（Φφdxt)），內徑可(ke)推算出。Pipe規(gui)(gui)格(ge)(ge)則用公(gong)稱管(guan)(guan)(guan)道(dao)規(gui)(gui)格(ge)(ge)NPSx表(biao)(biao)(biao)示(shi)，更完善的(de)(de)(de)表(biao)(biao)(biao)示(shi)應是(shi)(shi)(shi)：NPSxSchy，其中x表(biao)(biao)(biao)示(shi)直徑，y表(biao)(biao)(biao)示(shi)壁(bi)厚，它們僅是(shi)(shi)(shi)規(gui)(gui)格(ge)(ge)型號(hao)而非實際尺寸。當壁(bi)厚是(shi)(shi)(shi)標(biao)準規(gui)(gui)格(ge)(ge)sch40時(shi)，可(ke)省(sheng)略。具體內、外(wai)徑及壁(bi)厚尺寸數值要(yao)查表(biao)(biao)(biao)（ASME B36.10表(biao)(biao)(biao)2、A4及ASME B36.19表(biao)(biao)(biao)1）。相應的(de)(de)(de)翻譯(yi)方法還有(you)(you)(you) pipe：管(guan)(guan)(guan)道(dao)或配(pei)管(guan)(guan)(guan)；Tube：管(guan)(guan)(guan)子。在(zai)不區分時(shi)，統稱管(guan)(guan)(guan)材。

  Pipe管的通用(yong)技術(shu)條(tiao)件為(wei)A530，Tube管的通用(yong)技術(shu)條(tiao)件為(wei)A450，它們的主要(yao)差別如(ru)下：A530：壁(bi)厚(hou)用(yong)公(gong)稱壁(bi)厚(hou)表示(shi)，壁(bi)厚(hou)的允(yun)(yun)許偏(pian)(pian)差±12.5％，外徑的允(yun)(yun)許偏(pian)(pian)差控(kong)制較(jiao)松（如(ru)上(shang)偏(pian)(pian)差最(zui)小為(wei)0.4mm），對于擴口(kou)試(shi)驗、卷邊(bian)試(shi)驗、硬度均(jun)沒有要(yao)求。A450：壁(bi)厚(hou)用(yong)最(zui)小壁(bi)厚(hou)表示(shi)，壁(bi)厚(hou)的允(yun)(yun)許偏(pian)(pian)差負公(gong)差位零，外徑的允(yun)(yun)許偏(pian)(pian)差控(kong)制較(jiao)嚴（如(ru)上(shang)偏(pian)(pian)差最(zui)大為(wei)0.4mm），對于擴口(kou)試(shi)驗、卷邊(bian)試(shi)驗、硬度均(jun)有要(yao)求。

  Pipe管(guan)(guan)(guan)(guan)和(he)Tube管(guan)(guan)(guan)(guan)的(de)(de)(de)規范中(zhong)有自己的(de)(de)(de)技術要求。對(dui)于(yu)一(yi)般管(guan)(guan)(guan)(guan)線具體用(yong)Tube 管(guan)(guan)(guan)(guan)還是用(yong)Pipe管(guan)(guan)(guan)(guan)，很難給出(chu)明確(que)的(de)(de)(de)界限，但對(dui)于(yu)脹接(jie)的(de)(de)(de)換熱器(qi)管(guan)(guan)(guan)(guan)、爐管(guan)(guan)(guan)(guan)、儀表的(de)(de)(de)卡套連接(jie)管(guan)(guan)(guan)(guan)必須(xu)用(yong)Tube管(guan)(guan)(guan)(guan)，對(dui)于(yu)焊接(jie)的(de)(de)(de)管(guan)(guan)(guan)(guan)子(zi)用(yong)Tube 管(guan)(guan)(guan)(guan)和(he)Pipe管(guan)(guan)(guan)(guan)一(yi)般都可(ke)以，由于(yu)Tube管(guan)(guan)(guan)(guan)的(de)(de)(de)制造(zao)檢驗要求更為嚴格，可(ke)以用(yong)在壓(ya)力溫度更為苛刻的(de)(de)(de)工況，價格也較貴。

  ASME在制(zhi)定這段規則時，著眼于(yu)Pipe管和Tube管用(yong)途的性(xing)質(zhi)。在鍋爐(lu)和壓力(li)容器范圍內，Tube主(zhu)要著眼于(yu)內外傳(chuan)導熱量、熱交換用(yong)途，而(er)Pipe則主(zhu)要立足于(yu)將受壓介質(zhi)從一(yi)個地(di)方輸(shu)送到(dao)另(ling)一(yi)個地(di)方的功能。

  Tube可以是任何截面(mian)形狀，Pipe要(yao)是圓的(de)截面(mian)。Pipe是以公稱直徑定(ding)義，Tube是以外徑和壁厚定(ding)義，Pipe可以焊接、車螺紋，Tube只能用(yong)壓緊接頭(tou)（compress joint type）的(de)管件(jian)（fitting）連接。Pipe與(yu)Tube的(de)比較(jiao)見表4.2.5。