膨(peng)脹(zhang)節(jie)習慣上也叫補(bu)償(chang)器(qi)(qi)(qi)，或(huo)伸縮節(jie)。由(you)構成(cheng)其(qi)工作主體(ti)的(de)波紋管(guan)(guan)(guan)(guan)(guan)(guan)(一種(zhong)彈性(xing)元件)和(he)端管(guan)(guan)(guan)(guan)(guan)(guan)、支架、法蘭、導管(guan)(guan)(guan)(guan)(guan)(guan)等(deng)(deng)附(fu)件組成(cheng)。 膨(peng)脹(zhang)節(jie)是為了補(bu)償(chang)因溫(wen)度(du)(du)差與(yu)機(ji)械振動引起(qi)的(de)附(fu)加應(ying)力，而(er)設置在容(rong)器(qi)(qi)(qi)殼體(ti)或(huo)管(guan)(guan)(guan)(guan)(guan)(guan)道(dao)(dao)(dao)上的(de)一種(zhong)撓(nao)性(xing)結構。利用(yong)其(qi)工作主體(ti)波紋管(guan)(guan)(guan)(guan)(guan)(guan)的(de)有效伸縮變(bian)形，以(yi)吸(xi)收管(guan)(guan)(guan)(guan)(guan)(guan)線(xian)、導管(guan)(guan)(guan)(guan)(guan)(guan)、容(rong)器(qi)(qi)(qi)等(deng)(deng)由(you)熱(re)脹(zhang)冷縮等(deng)(deng)原因而(er)產生(sheng)的(de)尺(chi)寸變(bian)化，或(huo)補(bu)償(chang)管(guan)(guan)(guan)(guan)(guan)(guan)線(xian)、導管(guan)(guan)(guan)(guan)(guan)(guan)、容(rong)器(qi)(qi)(qi)等(deng)(deng)的(de)軸向、橫向和(he)角(jiao)向位(wei)移(yi)。也可用(yong)于降噪減振。供熱(re)上，為了防止供熱(re)管(guan)(guan)(guan)(guan)(guan)(guan)道(dao)(dao)(dao)升(sheng)溫(wen)時，由(you)于熱(re)伸長或(huo)溫(wen)度(du)(du)應(ying)力而(er)引起(qi)管(guan)(guan)(guan)(guan)(guan)(guan)道(dao)(dao)(dao)變(bian)形或(huo)破壞，需要在管(guan)(guan)(guan)(guan)(guan)(guan)道(dao)(dao)(dao)上設置補(bu)償(chang)器(qi)(qi)(qi)，以(yi)補(bu)償(chang)管(guan)(guan)(guan)(guan)(guan)(guan)道(dao)(dao)(dao)的(de)熱(re)伸長，從而(er)減小管(guan)(guan)(guan)(guan)(guan)(guan)壁的(de)應(ying)力和(he)作用(yong)在閥(fa)件或(huo)支架結構上的(de)作用(yong)力。