不銹(xiu)鋼管件(jian)在管系中起著改變(bian)(bian)(bian)走向、改變(bian)(bian)(bian)標高或(huo)改變(bian)(bian)(bian)直徑、封閉管端(duan)以(yi)及由主管上引出支管的(de)作(zuo)用。在石油化工裝置中管道品種(zhong)多，管系復雜(za)、形狀(zhuang)各異、簡(jian)繁不等(deng)，所用的(de)管件(jian)品種(zhong)、材(cai)質、數量也(ye)就很多，選用時需(xu)要考慮的(de)因(yin)素也(ye)很復雜(za)。

  非金屬管件和襯里管件的標準化程度不如不銹鋼管件高，使用時要注意各制造廠在制造工藝、規格尺寸、各種性能等方面的差異。本節主要介紹鋼(gang)制管(guan)件(jian)，需要選用非金屬管件和襯里管件時可從有關的標準規范中查找。

  管件(jian)的用途(tu)見表4-25。

  根據管(guan)(guan)(guan)(guan)(guan)件(jian)(jian)(jian)(jian)端部連接(jie)形式可(ke)將管(guan)(guan)(guan)(guan)(guan)件(jian)(jian)(jian)(jian)分為對焊連接(jie)管(guan)(guan)(guan)(guan)(guan)件(jian)(jian)(jian)(jian)（簡稱(cheng)對焊管(guan)(guan)(guan)(guan)(guan)件(jian)(jian)(jian)(jian)）、承(cheng)(cheng)插焊連接(jie)管(guan)(guan)(guan)(guan)(guan)件(jian)(jian)(jian)(jian)（簡稱(cheng)承(cheng)(cheng)插焊管(guan)(guan)(guan)(guan)(guan)件(jian)(jian)(jian)(jian)）、螺(luo)紋(wen)(wen)連接(jie)管(guan)(guan)(guan)(guan)(guan)件(jian)(jian)(jian)(jian)（簡稱(cheng)螺(luo)紋(wen)(wen)管(guan)(guan)(guan)(guan)(guan)件(jian)(jian)(jian)(jian)）、法蘭連接(jie)管(guan)(guan)(guan)(guan)(guan)件(jian)(jian)(jian)(jian)以及其他管(guan)(guan)(guan)(guan)(guan)件(jian)(jian)(jian)(jian)。

  壓力(li)管道(dao)設計中(zhong)，常用(yong)(yong)對(dui)焊(han)管件、支管臺、承(cheng)插焊(han)及(ji)螺紋連接管件的(de)形式。法(fa)蘭管件多用(yong)(yong)于特殊場合，使(shi)用(yong)(yong)范圍及(ji)數量相對(dui)比(bi)較(jiao)少(shao)。需要時可根據《鋼制法(fa)蘭管件》（GB／T17185）的(de)規定選用(yong)(yong)。