一、夾套管材料的設計

 ①. 夾套管的內管應采用無縫鋼管，套管可采用無縫鋼管或焊接鋼管。

 ②. 夾(jia)套管(guan)中與(yu)內管(guan)連接的管(guan)件應與(yu)內管(guan)材(cai)質相同(tong)。

 ③. 當(dang)套(tao)管(guan)與內管(guan)之(zhi)間溫(wen)度差過(guo)大或(huo)(huo)材(cai)質(zhi)(zhi)不(bu)相同時，應對夾套(tao)管(guan)進行應力分(fen)析計算，如兩者(zhe)熱(re)脹差異(yi)產(chan)生的熱(re)應力超過(guo)許用(yong)值(zhi)時內管(guan)與套(tao)管(guan)宜(yi)采用(yong)同種材(cai)質(zhi)(zhi)或(huo)(huo)線膨脹系數(shu)相近的材(cai)質(zhi)(zhi)。

二、夾套管的安裝

  ①. 除夾套(tao)管(guan)(guan)(guan)(guan)(guan)的(de)供給管(guan)(guan)(guan)(guan)(guan)和回收管(guan)(guan)(guan)(guan)(guan)外(wai)，夾套(tao)管(guan)(guan)(guan)(guan)(guan)的(de)主體(ti)部分應進行預制(zhi)。管(guan)(guan)(guan)(guan)(guan)夾套(tao)預制(zhi)時，應預留(liu)調整(zheng)管(guan)(guan)(guan)(guan)(guan)段，其調節裕量宜為50～100mm，調整(zheng)管(guan)(guan)(guan)(guan)(guan)段的(de)接(jie)縫(feng)位(wei)置必須避開外(wai)開口處。內管(guan)(guan)(guan)(guan)(guan)焊(han)縫(feng)隱蔽型夾套(tao)管(guan)(guan)(guan)(guan)(guan)，在(zai)內管(guan)(guan)(guan)(guan)(guan)焊(han)縫(feng)處的(de)套(tao)管(guan)(guan)(guan)(guan)(guan)應留(liu)150mm長缺口，待內管(guan)(guan)(guan)(guan)(guan)焊(han)縫(feng)經100％射線(xian)檢測，經試壓(ya)合格后方可進行隱蔽作(zuo)業。

  ②. 管(guan)夾套經剖(pou)切(qie)后安裝(zhuang)時(shi)，縱向(xiang)焊縫應置(zhi)于(yu)易檢(jian)修部位(wei)。套管(guan)與內管(guan)間的間隙應均勻，并應按設計(ji)要求(qiu)焊接定位(wei)板。定位(wei)板不得妨礙套管(guan)與內管(guan)的伸(shen)縮(suo)。

  ③. 夾套(tao)管(guan)內管(guan)的(de)試(shi)驗(yan)壓(ya)力應按內部或(huo)外部壓(ya)力高者的(de)1.5倍確定，夾套(tao)管(guan)套(tao)管(guan)的(de)試(shi)驗(yan)壓(ya)力應為(wei)套(tao)管(guan)設(she)計壓(ya)力的(de)1.5倍。被加熱管(guan)道(dao)應經(jing)無損探傷合格及水(shui)壓(ya)試(shi)驗(yan)合格后(hou)方可焊接套(tao)管(guan)。

  ④. 導(dao)熱油(you)管線的要求：宜(yi)采(cai)用(yong)(yong)(yong)焊(han)接(jie)(jie)，禁(jin)(jin)(jin)用(yong)(yong)(yong)螺紋連接(jie)(jie)，禁(jin)(jin)(jin)用(yong)(yong)(yong)有縫鋼管；應采(cai)用(yong)(yong)(yong)對(dui)焊(han)法蘭；宜(yi)采(cai)用(yong)(yong)(yong)鑄(zhu)鋼高(gao)溫閥(fa)門。宜(yi)采(cai)用(yong)(yong)(yong)柔(rou)性石墨纏繞墊片；禁(jin)(jin)(jin)用(yong)(yong)(yong)有色金(jin)屬。