短(duan)(duan)(duan)節(jie)是長(chang)度小于12in(0.3m),兩端(duan)或一端(duan)有螺(luo)(luo)(luo)紋(wen)(wen)(wen)(wen)(wen)并(bing)便于進行(xing)焊(han)接(jie)(jie)(jie)或機械連接(jie)(jie)(jie)的(de)一段管(guan)(guan)(guan)子(zi)。當長(chang)度在12in(0.3m)以上時(shi),則被稱為短(duan)(duan)(duan)管(guan)(guan)(guan)(cut pipe)。普通類型(xing)的(de)短(duan)(duan)(duan)節(jie)是全外(wai)牙(ya)型(xing),螺(luo)(luo)(luo)紋(wen)(wen)(wen)(wen)(wen)接(jie)(jie)(jie)口的(de)長(chang)度大約為標(biao)準管(guan)(guan)(guan)螺(luo)(luo)(luo)紋(wen)(wen)(wen)(wen)(wen)的(de)兩倍,且沒有肩部。任何長(chang)度的(de)帶肩螺(luo)(luo)(luo)紋(wen)(wen)(wen)(wen)(wen)管(guan)(guan)(guan)接(jie)(jie)(jie)頭的(de)兩個管(guan)(guan)(guan)螺(luo)(luo)(luo)紋(wen)(wen)(wen)(wen)(wen)間有肩部;短(duan)(duan)(duan)管(guan)(guan)(guan)螺(luo)(luo)(luo)紋(wen)(wen)(wen)(wen)(wen)管(guan)(guan)(guan)接(jie)(jie)(jie)頭是比(bi)全外(wai)牙(ya)型(xing)螺(luo)(luo)(luo)紋(wen)(wen)(wen)(wen)(wen)管(guan)(guan)(guan)接(jie)(jie)(jie)頭稍長(chang)的(de)帶肩螺(luo)(luo)(luo)紋(wen)(wen)(wen)(wen)(wen)管(guan)(guan)(guan)接(jie)(jie)(jie)頭,且對于不同管(guan)(guan)(guan)徑的(de)管(guan)(guan)(guan)子(zi)的(de)特(te)定長(chang)度均要符合制造商標(biao)準。長(chang)螺(luo)(luo)(luo)紋(wen)(wen)(wen)(wen)(wen)管(guan)(guan)(guan)接(jie)(jie)(jie)頭是比(bi)短(duan)(duan)(duan)節(jie)長(chang)的(de)切成特(te)定長(chang)度的(de)短(duan)(duan)(duan)節(jie)。典型(xing)短(duan)(duan)(duan)節(jie)見圖4.6.15。
①. 變(bian)(bian)徑短接(jie)管(也稱異(yi)型短節,漸(jian)縮管)(swage)與大小頭(異(yi)徑管)相同(tong),用以減小管線口(kou)徑,但是變(bian)(bian)徑短接(jie)管可設計為螺紋或者承(cheng)插焊連接(jie)。螺紋變(bian)(bian)徑短接(jie)管有陽螺紋(male threads 或者 external treads)。
②. 變徑短接管和異徑管一(yi)樣有同(tong)心(xin)和偏心(xin)。
③. 螺紋(wen)變(bian)(bian)徑短(duan)接(jie)管(screwed swage)有螺紋(wen)端(duan)(duan)(duan)(thread ends,TE),承插(cha)焊變(bian)(bian)徑短(duan)接(jie)管有平端(duan)(duan)(duan)(plain ends,TE),對(dui)(dui)焊變(bian)(bian)徑短(duan)接(jie)管有對(dui)(dui)焊坡口端(duan)(duan)(duan)(beveled ends,BE)。變(bian)(bian)徑短(duan)接(jie)管大端(duan)(duan)(duan)及小(xiao)(xiao)端(duan)(duan)(duan)分別有平端(duan)(duan)(duan)、坡口端(duan)(duan)(duan)、錐管外螺紋(wen)端(duan)(duan)(duan)三種(zhong):大、小(xiao)(xiao)端(duan)(duan)(duan)的各種(zhong)組合共計有九種(zhong)配合可能(neng),如表4.6.14所示。典型變(bian)(bian)徑短(duan)接(jie)管見圖4.6.16。