常有管(guan)(guan)(guan)道設計(ji)人員(yuan)向筆(bi)者咨(zi)詢Pipe與Tube管(guan)(guan)(guan)道的(de)區別(bie)。在ASME B31.1(動力(li)管(guan)(guan)(guan)道)第100.2節(jie)中(zhong)有詳細的(de)定義。Pipe是(shi)(shi)有圓(yuan)形(xing)截(jie)面(mian)的(de)空心制(zhi)品(pin);Tube是(shi)(shi)具有連(lian)續周圓(yuan)形(xing)或任何其(qi)截(jie)面(mian)形(xing)狀(zhuang)的(de)空心制(zhi)品(pin)。在規格表(biao)(biao)(biao)示(shi)(shi)上(shang),Tube的(de)外徑(jing)、內(nei)徑(jing)和壁厚(hou)可(ke)用(yong)兩個(ge)獨(du)立參(can)數(shu)表(biao)(biao)(biao)示(shi)(shi),即國內(nei)常用(yong)的(de)外徑(jing)x壁厚(hou)(Φφdxt)),內(nei)徑(jing)可(ke)推(tui)算出。Pipe規格則(ze)用(yong)公稱管(guan)(guan)(guan)道規格NPSx表(biao)(biao)(biao)示(shi)(shi),更完善(shan)的(de)表(biao)(biao)(biao)示(shi)(shi)應是(shi)(shi):NPSxSchy,其(qi)中(zhong)x表(biao)(biao)(biao)示(shi)(shi)直徑(jing),y表(biao)(biao)(biao)示(shi)(shi)壁厚(hou),它(ta)們僅是(shi)(shi)規格型號而(er)非(fei)實際尺寸(cun)。當壁厚(hou)是(shi)(shi)標準規格sch40時,可(ke)省略。具體內(nei)、外徑(jing)及壁厚(hou)尺寸(cun)數(shu)值(zhi)要查表(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)翻譯方法還(huan)有 pipe:管(guan)(guan)(guan)道或配管(guan)(guan)(guan);Tube:管(guan)(guan)(guan)子。在不區分時,統稱管(guan)(guan)(guan)材。
Pipe管的(de)通用技術條(tiao)件為(wei)A530,Tube管的(de)通用技術條(tiao)件為(wei)A450,它(ta)們(men)的(de)主要(yao)差(cha)(cha)別如下(xia):A530:壁(bi)(bi)(bi)厚(hou)(hou)用公(gong)稱壁(bi)(bi)(bi)厚(hou)(hou)表示,壁(bi)(bi)(bi)厚(hou)(hou)的(de)允許(xu)偏(pian)(pian)差(cha)(cha)±12.5%,外徑的(de)允許(xu)偏(pian)(pian)差(cha)(cha)控制(zhi)較(jiao)松(song)(如上(shang)偏(pian)(pian)差(cha)(cha)最(zui)小為(wei)0.4mm),對(dui)(dui)于擴口試(shi)驗(yan)(yan)(yan)、卷(juan)邊(bian)(bian)試(shi)驗(yan)(yan)(yan)、硬度均沒有(you)要(yao)求。A450:壁(bi)(bi)(bi)厚(hou)(hou)用最(zui)小壁(bi)(bi)(bi)厚(hou)(hou)表示,壁(bi)(bi)(bi)厚(hou)(hou)的(de)允許(xu)偏(pian)(pian)差(cha)(cha)負(fu)公(gong)差(cha)(cha)位零,外徑的(de)允許(xu)偏(pian)(pian)差(cha)(cha)控制(zhi)較(jiao)嚴(yan)(如上(shang)偏(pian)(pian)差(cha)(cha)最(zui)大(da)為(wei)0.4mm),對(dui)(dui)于擴口試(shi)驗(yan)(yan)(yan)、卷(juan)邊(bian)(bian)試(shi)驗(yan)(yan)(yan)、硬度均有(you)要(yao)求。
Pipe管(guan)(guan)(guan)和Tube管(guan)(guan)(guan)的(de)(de)規范中有自己的(de)(de)技術要(yao)求。對(dui)(dui)于(yu)一般管(guan)(guan)(guan)線(xian)具(ju)體用(yong)(yong)(yong)Tube 管(guan)(guan)(guan)還(huan)是用(yong)(yong)(yong)Pipe管(guan)(guan)(guan),很難給出明確的(de)(de)界限,但對(dui)(dui)于(yu)脹接(jie)的(de)(de)換熱器管(guan)(guan)(guan)、爐管(guan)(guan)(guan)、儀表的(de)(de)卡套連接(jie)管(guan)(guan)(guan)必須用(yong)(yong)(yong)Tube管(guan)(guan)(guan),對(dui)(dui)于(yu)焊接(jie)的(de)(de)管(guan)(guan)(guan)子用(yong)(yong)(yong)Tube 管(guan)(guan)(guan)和Pipe管(guan)(guan)(guan)一般都可(ke)以,由于(yu)Tube管(guan)(guan)(guan)的(de)(de)制造檢驗要(yao)求更為(wei)嚴(yan)格,可(ke)以用(yong)(yong)(yong)在壓力溫度更為(wei)苛刻的(de)(de)工況,價格也較貴。
ASME在制定這段規則時,著(zhu)眼于Pipe管和Tube管用(yong)途(tu)的性質(zhi)。在鍋爐(lu)和壓力容器范圍(wei)內(nei),Tube主(zhu)要(yao)著(zhu)眼于內(nei)外(wai)傳導熱(re)量、熱(re)交換用(yong)途(tu),而Pipe則主(zhu)要(yao)立足(zu)于將受壓介質(zhi)從一個地方(fang)輸送到另一個地方(fang)的功能。
Tube可以是(shi)任(ren)何截面形(xing)狀(zhuang),Pipe要是(shi)圓的(de)截面。Pipe是(shi)以公(gong)稱直徑定(ding)義(yi),Tube是(shi)以外徑和壁厚定(ding)義(yi),Pipe可以焊接(jie)(jie)、車螺紋,Tube只能(neng)用壓緊接(jie)(jie)頭(tou)(compress joint type)的(de)管件(fitting)連接(jie)(jie)。Pipe與Tube的(de)比(bi)較(jiao)見表4.2.5。