波紋管膨脹節是用金屬波紋管制成的一種膨脹節。它能沿管道軸線方向伸縮，也允許少量彎曲。圖(tu)2為常(chang)見的(de)(de)軸向(xiang)式(shi)波(bo)紋(wen)(wen)管(guan)(guan)(guan)(guan)膨(peng)(peng)脹節，用(yong)(yong)在管(guan)(guan)(guan)(guan)道上進行(xing)軸向(xiang)長(chang)度(du)補(bu)(bu)償(chang)。為了防止(zhi)超(chao)過(guo)允許的(de)(de)補(bu)(bu)償(chang)量，在波(bo)紋(wen)(wen)管(guan)(guan)(guan)(guan)兩端設置有(you)保護拉桿或保護環(huan)，在與它(ta)連接(jie)的(de)(de)兩端管(guan)(guan)(guan)(guan)道上設置導向(xiang)支(zhi)架。另(ling)外還有(you)轉(zhuan)角(jiao)式(shi)和(he)橫(heng)向(xiang)式(shi)膨(peng)(peng)脹節，可(ke)用(yong)(yong)來補(bu)(bu)償(chang)管(guan)(guan)(guan)(guan)道的(de)(de)轉(zhuan)角(jiao)變(bian)(bian)形和(he)橫(heng)向(xiang)變(bian)(bian)形。這類膨(peng)(peng)脹節的(de)(de)優點(dian)是(shi)節省空間，節約材(cai)料，便于(yu)標準化和(he)批量生產，缺點(dian)是(shi)壽命較短。波(bo)紋(wen)(wen)管(guan)(guan)(guan)(guan)膨(peng)(peng)脹節一般(ban)用(yong)(yong)于(yu)溫(wen)度(du)和(he)壓(ya)力不很高(gao)、長(chang)度(du)較短的(de)(de)管(guan)(guan)(guan)(guan)道上。隨(sui)著波(bo)紋(wen)(wen)管(guan)(guan)(guan)(guan)生產技術水平的(de)(de)提(ti)高(gao)，這類膨(peng)(peng)脹節的(de)(de)應用(yong)(yong)范圍正在擴(kuo)大。目前，波(bo)紋(wen)(wen)管(guan)(guan)(guan)(guan)膨(peng)(peng)脹節可(ke)用(yong)(yong)在最(zui)高(gao)壓(ya)力6.0兆帕(pa)的(de)(de)管(guan)(guan)(guan)(guan)系中。