一、夾套(tao)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. 夾套管(guan)中與(yu)內管(guan)連(lian)接的管(guan)件應與(yu)內管(guan)材質相同。

 ③. 當套(tao)管(guan)(guan)(guan)與內管(guan)(guan)(guan)之(zhi)間溫(wen)度差過(guo)大或材(cai)質(zhi)(zhi)不相(xiang)同時，應對夾套(tao)管(guan)(guan)(guan)進行應力(li)分(fen)析(xi)計(ji)算，如兩者(zhe)熱(re)脹差異(yi)產生的熱(re)應力(li)超(chao)過(guo)許(xu)用值時內管(guan)(guan)(guan)與套(tao)管(guan)(guan)(guan)宜(yi)采用同種材(cai)質(zhi)(zhi)或線膨脹系數相(xiang)近的材(cai)質(zhi)(zhi)。

二、夾套管的(de)安裝

  ①. 除(chu)夾套管(guan)(guan)(guan)(guan)的供給管(guan)(guan)(guan)(guan)和回收(shou)管(guan)(guan)(guan)(guan)外，夾套管(guan)(guan)(guan)(guan)的主體部分應進行(xing)預(yu)(yu)制(zhi)。管(guan)(guan)(guan)(guan)夾套預(yu)(yu)制(zhi)時，應預(yu)(yu)留調(diao)(diao)整管(guan)(guan)(guan)(guan)段(duan)，其調(diao)(diao)節裕量宜為50～100mm，調(diao)(diao)整管(guan)(guan)(guan)(guan)段(duan)的接縫(feng)位(wei)置必須避開外開口處。內管(guan)(guan)(guan)(guan)焊縫(feng)隱(yin)蔽型夾套管(guan)(guan)(guan)(guan)，在內管(guan)(guan)(guan)(guan)焊縫(feng)處的套管(guan)(guan)(guan)(guan)應留150mm長缺口，待內管(guan)(guan)(guan)(guan)焊縫(feng)經100％射線(xian)檢測，經試壓合(he)格后(hou)方可進行(xing)隱(yin)蔽作業(ye)。

  ②. 管(guan)夾(jia)套經剖切(qie)后安(an)裝時，縱向焊縫應置于易檢(jian)修部位。套管(guan)與(yu)內(nei)管(guan)間的間隙應均(jun)勻，并應按設計要(yao)求焊接定位板。定位板不得妨礙套管(guan)與(yu)內(nei)管(guan)的伸(shen)縮(suo)。

  ③. 夾套管(guan)內(nei)管(guan)的(de)試驗(yan)壓(ya)(ya)(ya)力應按內(nei)部(bu)或外部(bu)壓(ya)(ya)(ya)力高者(zhe)的(de)1.5倍確定，夾套管(guan)套管(guan)的(de)試驗(yan)壓(ya)(ya)(ya)力應為套管(guan)設計壓(ya)(ya)(ya)力的(de)1.5倍。被加熱(re)管(guan)道應經無損(sun)探(tan)傷合格(ge)及水壓(ya)(ya)(ya)試驗(yan)合格(ge)后方可焊接套管(guan)。

  ④. 導熱油管(guan)線的要(yao)求：宜采用(yong)(yong)焊接，禁(jin)用(yong)(yong)螺紋連接，禁(jin)用(yong)(yong)有縫鋼管(guan)；應(ying)采用(yong)(yong)對焊法蘭；宜采用(yong)(yong)鑄(zhu)鋼高(gao)溫閥門。宜采用(yong)(yong)柔(rou)性(xing)石墨纏繞(rao)墊片；禁(jin)用(yong)(yong)有色金屬。