補(bu)(bu)償(chang)(chang)器(qi)習(xi)慣上也叫(jiao)膨脹節，或(huo)(huo)伸縮節。由構(gou)成其(qi)工(gong)作主體(ti)(ti)的波(bo)紋管(guan)(guan)(guan)(guan)（一種(zhong)彈性元件(jian)）和端管(guan)(guan)(guan)(guan)、支架(jia)、法蘭、導管(guan)(guan)(guan)(guan)等(deng)附(fu)件(jian)組成。 屬于一種(zhong)補(bu)(bu)償(chang)(chang)元件(jian)。利用(yong)(yong)其(qi)工(gong)作主體(ti)(ti)波(bo)紋管(guan)(guan)(guan)(guan)的有效(xiao)伸縮變(bian)形(xing)，以(yi)吸收管(guan)(guan)(guan)(guan)線、導管(guan)(guan)(guan)(guan)、容器(qi)等(deng)由熱脹冷縮等(deng)原因而(er)產生的尺寸(cun)變(bian)化，或(huo)(huo)補(bu)(bu)償(chang)(chang)管(guan)(guan)(guan)(guan)線、導管(guan)(guan)(guan)(guan)、容器(qi)等(deng)的軸向、橫(heng)向和角向位(wei)移。也可用(yong)(yong)于降噪(zao)減(jian)振。在現代工(gong)業中用(yong)(yong)途廣(guang)泛。供熱上，為(wei)了防止(zhi)供熱管(guan)(guan)(guan)(guan)道(dao)升溫時，由于熱伸長(chang)或(huo)(huo)溫度應(ying)力而(er)引起管(guan)(guan)(guan)(guan)道(dao)變(bian)形(xing)或(huo)(huo)破壞，需要在管(guan)(guan)(guan)(guan)道(dao)上設(she)置補(bu)(bu)償(chang)(chang)器(qi)，以(yi)補(bu)(bu)償(chang)(chang)管(guan)(guan)(guan)(guan)道(dao)的熱伸長(chang)，從(cong)而(er)減(jian)小管(guan)(guan)(guan)(guan)壁的應(ying)力和作用(yong)(yong)在閥件(jian)或(huo)(huo)支架(jia)結構(gou)上的作用(yong)(yong)力。