不銹鋼管件在管系(xi)中起著改變(bian)走向(xiang)、改變(bian)標高(gao)或改變(bian)直(zhi)徑、封(feng)閉管端以及由(you)主(zhu)管上(shang)引(yin)出支管的作用(yong)。在石油化工(gong)裝(zhuang)置中管道品種多，管系(xi)復雜、形狀(zhuang)各異(yi)、簡繁不等(deng)，所用(yong)的管件品種、材(cai)質(zhi)、數量也就很(hen)多，選(xuan)用(yong)時需要(yao)考慮的因素也很(hen)復雜。

  非金屬管件和襯里管件的標準化程度不如不(bu)銹(xiu)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。本節主要介紹鋼制(zhi)管件，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)的用途見表4-25。

  根(gen)據管(guan)(guan)(guan)(guan)(guan)件(jian)(jian)(jian)(jian)端部連接(jie)形式可將管(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(jian)稱(cheng)(cheng)對焊管(guan)(guan)(guan)(guan)(guan)件(jian)(jian)(jian)(jian)）、承(cheng)(cheng)插(cha)焊連接(jie)管(guan)(guan)(guan)(guan)(guan)件(jian)(jian)(jian)(jian)（簡(jian)稱(cheng)(cheng)承(cheng)(cheng)插(cha)焊管(guan)(guan)(guan)(guan)(guan)件(jian)(jian)(jian)(jian)）、螺(luo)紋連接(jie)管(guan)(guan)(guan)(guan)(guan)件(jian)(jian)(jian)(jian)（簡(jian)稱(cheng)(cheng)螺(luo)紋管(guan)(guan)(guan)(guan)(guan)件(jian)(jian)(jian)(jian)）、法蘭(lan)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)。

  壓力管(guan)道(dao)設計中，常用(yong)對焊管(guan)件(jian)(jian)、支管(guan)臺(tai)、承插(cha)焊及(ji)螺紋連接管(guan)件(jian)(jian)的形式。法(fa)蘭管(guan)件(jian)(jian)多用(yong)于特殊場合，使用(yong)范圍及(ji)數量相(xiang)對比較少。需要時可根據《鋼制法(fa)蘭管(guan)件(jian)(jian)》（GB／T17185）的規定選用(yong)。