短(duan)節(jie)是長(chang)(chang)度(du)(du)小于12in(0.3m),兩端(duan)或一端(duan)有(you)螺紋(wen)(wen)(wen)并便于進(jin)行焊接(jie)(jie)或機械連接(jie)(jie)的(de)一段(duan)管(guan)(guan)(guan)(guan)(guan)子(zi)。當長(chang)(chang)度(du)(du)在12in(0.3m)以(yi)上時,則被稱(cheng)為短(duan)管(guan)(guan)(guan)(guan)(guan)(cut pipe)。普通類型(xing)的(de)短(duan)節(jie)是全(quan)外牙型(xing),螺紋(wen)(wen)(wen)接(jie)(jie)口的(de)長(chang)(chang)度(du)(du)大約為標準管(guan)(guan)(guan)(guan)(guan)螺紋(wen)(wen)(wen)的(de)兩倍,且沒有(you)肩(jian)(jian)部(bu)。任何長(chang)(chang)度(du)(du)的(de)帶肩(jian)(jian)螺紋(wen)(wen)(wen)管(guan)(guan)(guan)(guan)(guan)接(jie)(jie)頭的(de)兩個管(guan)(guan)(guan)(guan)(guan)螺紋(wen)(wen)(wen)間有(you)肩(jian)(jian)部(bu);短(duan)管(guan)(guan)(guan)(guan)(guan)螺紋(wen)(wen)(wen)管(guan)(guan)(guan)(guan)(guan)接(jie)(jie)頭是比(bi)全(quan)外牙型(xing)螺紋(wen)(wen)(wen)管(guan)(guan)(guan)(guan)(guan)接(jie)(jie)頭稍長(chang)(chang)的(de)帶肩(jian)(jian)螺紋(wen)(wen)(wen)管(guan)(guan)(guan)(guan)(guan)接(jie)(jie)頭,且對于不(bu)同管(guan)(guan)(guan)(guan)(guan)徑的(de)管(guan)(guan)(guan)(guan)(guan)子(zi)的(de)特(te)定長(chang)(chang)度(du)(du)均要符合制造(zao)商標準。長(chang)(chang)螺紋(wen)(wen)(wen)管(guan)(guan)(guan)(guan)(guan)接(jie)(jie)頭是比(bi)短(duan)節(jie)長(chang)(chang)的(de)切成特(te)定長(chang)(chang)度(du)(du)的(de)短(duan)節(jie)。典型(xing)短(duan)節(jie)見圖4.6.15。
①. 變徑(jing)(jing)短接管(guan)(也稱異型短節,漸縮(suo)管(guan))(swage)與大(da)小頭(異徑(jing)(jing)管(guan))相同,用以減小管(guan)線口徑(jing)(jing),但是變徑(jing)(jing)短接管(guan)可設計為螺(luo)(luo)紋或者承插焊(han)連(lian)接。螺(luo)(luo)紋變徑(jing)(jing)短接管(guan)有(you)陽螺(luo)(luo)紋(male threads 或者 external treads)。
②. 變徑(jing)短接管和異徑(jing)管一樣有同心和偏心。
③. 螺紋變(bian)徑短(duan)接(jie)(jie)管(guan)(guan)(screwed swage)有螺紋端(duan)(duan)(duan)(thread ends,TE),承插焊變(bian)徑短(duan)接(jie)(jie)管(guan)(guan)有平(ping)端(duan)(duan)(duan)(plain ends,TE),對(dui)焊變(bian)徑短(duan)接(jie)(jie)管(guan)(guan)有對(dui)焊坡口端(duan)(duan)(duan)(beveled ends,BE)。變(bian)徑短(duan)接(jie)(jie)管(guan)(guan)大(da)端(duan)(duan)(duan)及小端(duan)(duan)(duan)分別有平(ping)端(duan)(duan)(duan)、坡口端(duan)(duan)(duan)、錐管(guan)(guan)外螺紋端(duan)(duan)(duan)三(san)種:大(da)、小端(duan)(duan)(duan)的(de)各(ge)種組(zu)合共計有九種配合可(ke)能(neng),如表4.6.14所示。典(dian)型變(bian)徑短(duan)接(jie)(jie)管(guan)(guan)見(jian)圖4.6.16。