35crmo厚壁鋼管中的DN表示(shi)什么意思?

DN一般用于35crmo厚壁鋼管中，DN是公稱通徑，公稱通徑(nominal diameter)，又稱平均外徑(mean outside diameter)。 公稱通徑是管路系統中所有管路附件用數字表示的尺寸，35crmo厚壁鋼管公稱通(tong)徑用字(zi)母“DN”后面緊跟一個數字(zi)標志。

35crmo厚壁鋼管公稱通徑是供參考用的一個方便的圓整數，與加工尺寸僅呈不嚴格的關系。 這是緣自金屬管的管璧很薄，管外徑與管內徑相差無幾，所以取管的外徑與35crmo厚壁鋼管的內徑(jing)(jing)(jing)之平均(jun)值(zhi)當作管(guan)(guan)(guan)徑(jing)(jing)(jing)稱(cheng)(cheng)呼。 DN是(shi)公(gong)(gong)(gong)稱(cheng)(cheng)通(tong)徑(jing)(jing)(jing)，公(gong)(gong)(gong)稱(cheng)(cheng)直(zhi)徑(jing)(jing)(jing) (或叫公(gong)(gong)(gong)稱(cheng)(cheng)通(tong)徑(jing)(jing)(jing)),就是(shi)各(ge)種管(guan)(guan)(guan)子與管(guan)(guan)(guan)路(lu)附件(jian)的通(tong)用(yong)口徑(jing)(jing)(jing)。同(tong)一(yi)公(gong)(gong)(gong)稱(cheng)(cheng)直(zhi)徑(jing)(jing)(jing)的管(guan)(guan)(guan)子與管(guan)(guan)(guan)路(lu)附件(jian)均(jun)能相(xiang)(xiang)互(hu)連接(jie)，具有互(hu)換性.它不(bu)(bu)是(shi)實際(ji)意義上的管(guan)(guan)(guan)道外徑(jing)(jing)(jing)或內徑(jing)(jing)(jing)，雖(sui)然其(qi)數值(zhi)跟(gen)管(guan)(guan)(guan)道內徑(jing)(jing)(jing)較為接(jie)近或相(xiang)(xiang)等(deng)；為了使管(guan)(guan)(guan)子、管(guan)(guan)(guan)件(jian)連接(jie)尺寸統一(yi)，采用(yong)公(gong)(gong)(gong)稱(cheng)(cheng)直(zhi)徑(jing)(jing)(jing)（公(gong)(gong)(gong)稱(cheng)(cheng)通(tong)徑(jing)(jing)(jing))。其(qi)公(gong)(gong)(gong)稱(cheng)(cheng)直(zhi)徑(jing)(jing)(jing)不(bu)(bu)是(shi)外徑(jing)(jing)(jing)，也(ye)不(bu)(bu)是(shi)內徑(jing)(jing)(jing)，而是(shi)近似普通(tong)35crmo厚壁(bi)(bi)鋼管(guan)(guan)(guan)內徑(jing)(jing)(jing)的一(yi)個名義尺寸。例如35crmo厚壁(bi)(bi)鋼管(guan)(guan)(guan) 每一(yi)公(gong)(gong)(gong)稱(cheng)(cheng)直(zhi)徑(jing)(jing)(jing)，對應一(yi)個外徑(jing)(jing)(jing)，其(qi)內徑(jing)(jing)(jing)數值(zhi)隨厚度(du)不(bu)(bu)同(tong)而不(bu)(bu)同(tong)。公(gong)(gong)(gong)稱(cheng)(cheng)直(zhi)徑(jing)(jing)(jing)可(ke)用(yong)公(gong)(gong)(gong)制mm表示，也(ye)可(ke)用(yong)英制in表示。管(guan)(guan)(guan)路(lu)附件(jian)也(ye)用(yong)公(gong)(gong)(gong)稱(cheng)(cheng)直(zhi)徑(jing)(jing)(jing)表示，意義同(tong)有縫管(guan)(guan)(guan)。

 (責(ze)任編(bian)輯(ji)：龍川(chuan)小編(bian))

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