從(cong)工(gong)(gong)程實(shi)踐中(zhong)出現的(de)(de)(de)質量(liang)(liang)問題(ti)來看(kan)，聚(ju)氨(an)(an)酯(zhi)保(bao)(bao)(bao)(bao)溫(wen)(wen)管(guan)(guan)(guan)保(bao)(bao)(bao)(bao)溫(wen)(wen)性能佳(jia)，熱(re)損(sun)失為傳統管(guan)(guan)(guan)材的(de)(de)(de)25%，可(ke)顯著(zhu)降(jiang)低成本，節(jie)約能源(yuan)。防(fang)水(shui)功能優異，聚(ju)氨(an)(an)酯(zhi)保(bao)(bao)(bao)(bao)溫(wen)(wen)管(guan)(guan)(guan)極好的(de)(de)(de)耐酸(suan)、耐堿(jian)(jian)、耐腐(fu)蝕。使用壽(shou)命長，可(ke)達(da)30-50年(nian)。聚(ju)氨(an)(an)酯(zhi)保(bao)(bao)(bao)(bao)溫(wen)(wen)管(guan)(guan)(guan)保(bao)(bao)(bao)(bao)溫(wen)(wen)性能佳(jia)，熱(re)損(sun)失為傳統管(guan)(guan)(guan)材的(de)(de)(de)25%，可(ke)顯著(zhu)降(jiang)低成本，節(jie)約能源(yuan)。防(fang)水(shui)功能優異，聚(ju)氨(an)(an)酯(zhi)保(bao)(bao)(bao)(bao)溫(wen)(wen)管(guan)(guan)(guan)極好的(de)(de)(de)耐酸(suan)、耐堿(jian)(jian)、耐腐(fu)蝕。使用壽(shou)命長，可(ke)達(da)30-50年(nian)。管(guan)(guan)(guan)徑(jing)可(ke)大可(ke)小，從(cong)DN15-DN600；保(bao)(bao)(bao)(bao)溫(wen)(wen)厚(hou)度(du)(du)可(ke)厚(hou)可(ke)薄，從(cong)15--500mm高溫(wen)(wen)預(yu)制(zhi)直(zhi)埋保(bao)(bao)(bao)(bao)溫(wen)(wen)管(guan)(guan)(guan)從(cong)節(jie)約能源(yuan)、降(jiang)低造價、縮(suo)短施工(gong)(gong)周期、保(bao)(bao)(bao)(bao)護環(huan)境(jing)多方面來看(kan)，不僅具有傳統地溝和(he)架空敷(fu)設管(guan)(guan)(guan)道(dao)(dao)難(nan)以比擬的(de)(de)(de)技(ji)術和(he)實(shi)用性能，聚(ju)氨(an)(an)酯(zhi)保(bao)(bao)(bao)(bao)溫(wen)(wen)管(guan)(guan)(guan)而且(qie)具有顯著(zhu)的(de)(de)(de)社會(hui)效(xiao)益(yi)和(he)經(jing)濟效(xiao)益(yi)，但一(yi)個優質的(de)(de)(de)直(zhi)埋供熱(re)管(guan)(guan)(guan)道(dao)(dao)工(gong)(gong)程還(huan)必(bi)須具備(bei)設計(ji)合理、保(bao)(bao)(bao)(bao)溫(wen)(wen)管(guan)(guan)(guan)道(dao)(dao)質量(liang)(liang)可(ke)靠1精心施工(gong)(gong)3個條(tiao)件。由于直(zhi)埋供熱(re)技(ji)術在我國起步較晚，聚(ju)氨(an)(an)酯(zhi)保(bao)(bao)(bao)(bao)溫(wen)(wen)管(guan)(guan)(guan)以上(shang)3個條(tiao)件尚需不斷完善。應在設計(ji)和(he)施工(gong)(gong)中(zhong)特(te)別注意以下幾個問題(ti)：無補償敷(fu)設方式的(de)(de)(de)基本原(yuan)理：在安裝(zhuang)管(guan)(guan)(guan)道(dao)(dao)時，首(shou)先(xian)給(gei)管(guan)(guan)(guan)道(dao)(dao)加熱(re)到一(yi)定溫(wen)(wen)度(du)(du)，然后將管(guan)(guan)(guan)道(dao)(dao)焊接固定，當管(guan)(guan)(guan)道(dao)(dao)恢(hui)復到安裝(zhuang)溫(wen)(wen)度(du)(du)時(溫(wen)(wen)度(du)(du)降(jiang)低)，管(guan)(guan)(guan)道(dao)(dao)預(yu)先(xian)承受了一(yi)定的(de)(de)(de)拉應力。

    當(dang)管(guan)(guan)(guan)道(dao)(dao)(dao)通熱(re)工作(zuo)時(shi)(shi)(shi)，隨著溫(wen)(wen)(wen)(wen)度(du)(du)(du)(du)的(de)(de)升高，管(guan)(guan)(guan)道(dao)(dao)(dao)應(ying)力(li)(li)(li)(li)(li)為零(ling)(ling)，當(dang)繼續升溫(wen)(wen)(wen)(wen)時(shi)(shi)(shi)，管(guan)(guan)(guan)道(dao)(dao)(dao)的(de)(de)壓(ya)應(ying)力(li)(li)(li)(li)(li)增加，當(dang)溫(wen)(wen)(wen)(wen)度(du)(du)(du)(du)升到(dao)(dao)工作(zuo)溫(wen)(wen)(wen)(wen)度(du)(du)(du)(du)時(shi)(shi)(shi)，管(guan)(guan)(guan)道(dao)(dao)(dao)的(de)(de)壓(ya)應(ying)力(li)(li)(li)(li)(li)(熱(re)應(ying)力(li)(li)(li)(li)(li))仍小(xiao)于許用(yong)應(ying)力(li)(li)(li)(li)(li)。這(zhe)樣(yang)，管(guan)(guan)(guan)道(dao)(dao)(dao)可以不用(yong)補(bu)償裝置(zhi)而正常工作(zuo)了。這(zhe)種(zhong)無(wu)補(bu)償方(fang)(fang)式(shi)應(ying)用(yong)第四強度(du)(du)(du)(du)理(li)論，聚氨酯保溫(wen)(wen)(wen)(wen)管(guan)(guan)(guan)施工時(shi)(shi)(shi)需(xu)要對管(guan)(guan)(guan)道(dao)(dao)(dao)預(yu)熱(re)，施工比較麻(ma)煩，但國內外已有大(da)量工程實踐，理(li)論計算(suan)可靠，能確保安(an)全(quan)。另一種(zhong)無(wu)補(bu)償方(fang)(fang)式(shi)是近幾年由沈(shen)陽(yang)煤氣熱(re)力(li)(li)(li)(li)(li)設(she)計院(yuan)提出的(de)(de)計算(suan)方(fang)(fang)法和應(ying)力(li)(li)(li)(li)(li)分類采用(yong)安(an)定性分析，應(ying)用(yong)第三強度(du)(du)(du)(du)理(li)論。這(zhe)種(zhong)方(fang)(fang)式(shi)充分發(fa)揮鋼(gang)材塑(su)性潛力(li)(li)(li)(li)(li)，施工方(fang)(fang)便，無(wu)需(xu)預(yu)熱(re)，應(ying)在設(she)計和施工中特(te)別注意(yi)以下幾個問題：無(wu)補(bu)償敷設(she)方(fang)(fang)式(shi)的(de)(de)基本原理(li)：在安(an)裝管(guan)(guan)(guan)道(dao)(dao)(dao)時(shi)(shi)(shi)，首先給管(guan)(guan)(guan)道(dao)(dao)(dao)加熱(re)到(dao)(dao)一定溫(wen)(wen)(wen)(wen)度(du)(du)(du)(du)，然(ran)后(hou)將管(guan)(guan)(guan)道(dao)(dao)(dao)焊接固定，當(dang)管(guan)(guan)(guan)道(dao)(dao)(dao)恢復到(dao)(dao)安(an)裝溫(wen)(wen)(wen)(wen)度(du)(du)(du)(du)時(shi)(shi)(shi)(溫(wen)(wen)(wen)(wen)度(du)(du)(du)(du)降低(di))，管(guan)(guan)(guan)道(dao)(dao)(dao)預(yu)先承受(shou)了一定的(de)(de)拉應(ying)力(li)(li)(li)(li)(li)。當(dang)管(guan)(guan)(guan)道(dao)(dao)(dao)通熱(re)工作(zuo)時(shi)(shi)(shi)，隨著溫(wen)(wen)(wen)(wen)度(du)(du)(du)(du)的(de)(de)升高，管(guan)(guan)(guan)道(dao)(dao)(dao)應(ying)力(li)(li)(li)(li)(li)為零(ling)(ling)，當(dang)繼續升溫(wen)(wen)(wen)(wen)時(shi)(shi)(shi)，管(guan)(guan)(guan)道(dao)(dao)(dao)的(de)(de)壓(ya)應(ying)力(li)(li)(li)(li)(li)增加，當(dang)溫(wen)(wen)(wen)(wen)度(du)(du)(du)(du)升到(dao)(dao)工作(zuo)溫(wen)(wen)(wen)(wen)度(du)(du)(du)(du)時(shi)(shi)(shi)，管(guan)(guan)(guan)道(dao)(dao)(dao)的(de)(de)壓(ya)應(ying)力(li)(li)(li)(li)(li)(熱(re)應(ying)力(li)(li)(li)(li)(li))仍小(xiao)于許用(yong)應(ying)力(li)(li)(li)(li)(li)。這(zhe)樣(yang)，管(guan)(guan)(guan)道(dao)(dao)(dao)可以不用(yong)補(bu)償裝置(zhi)而正常工作(zuo)了。