補償(chang)(chang)器習(xi)慣上也叫膨脹節，或伸(shen)(shen)縮節。由構成其工(gong)(gong)作主體的(de)(de)波(bo)紋(wen)管(guan)(guan)(guan)(guan)(guan)（一(yi)種彈性元件(jian)(jian)）和端管(guan)(guan)(guan)(guan)(guan)、支架、法蘭、導管(guan)(guan)(guan)(guan)(guan)等(deng)附件(jian)(jian)組成。 屬于(yu)一(yi)種補償(chang)(chang)元件(jian)(jian)。利(li)用(yong)(yong)其工(gong)(gong)作主體波(bo)紋(wen)管(guan)(guan)(guan)(guan)(guan)的(de)(de)有效伸(shen)(shen)縮變(bian)形，以(yi)吸(xi)收管(guan)(guan)(guan)(guan)(guan)線、導管(guan)(guan)(guan)(guan)(guan)、容器等(deng)由熱(re)(re)(re)脹冷(leng)縮等(deng)原因而(er)(er)產生的(de)(de)尺寸變(bian)化，或補償(chang)(chang)管(guan)(guan)(guan)(guan)(guan)線、導管(guan)(guan)(guan)(guan)(guan)、容器等(deng)的(de)(de)軸向、橫向和角向位(wei)移。也可用(yong)(yong)于(yu)降噪減振。在(zai)現(xian)代(dai)工(gong)(gong)業中(zhong)用(yong)(yong)途廣(guang)泛。供(gong)熱(re)(re)(re)上，為了防止供(gong)熱(re)(re)(re)管(guan)(guan)(guan)(guan)(guan)道(dao)(dao)升溫(wen)時，由于(yu)熱(re)(re)(re)伸(shen)(shen)長或溫(wen)度應力(li)而(er)(er)引起管(guan)(guan)(guan)(guan)(guan)道(dao)(dao)變(bian)形或破壞，需要在(zai)管(guan)(guan)(guan)(guan)(guan)道(dao)(dao)上設置補償(chang)(chang)器，以(yi)補償(chang)(chang)管(guan)(guan)(guan)(guan)(guan)道(dao)(dao)的(de)(de)熱(re)(re)(re)伸(shen)(shen)長，從而(er)(er)減小管(guan)(guan)(guan)(guan)(guan)壁的(de)(de)應力(li)和作用(yong)(yong)在(zai)閥(fa)件(jian)(jian)或支架結構上的(de)(de)作用(yong)(yong)力(li)。