某管(guan)(guan)(guan)廊頂(ding)部大(da)口(kou)徑管(guan)(guan)(guan)線呈現(xian)拱(gong)形(xing)狀(zhuang),分析(xi)原因,是管(guan)(guan)(guan)廊頂(ding)部管(guan)(guan)(guan)道(dao)暴露在陽光下(xia),管(guan)(guan)(guan)道(dao)上(shang)部的溫度(du)和(he)下(xia)部的溫度(du)會不(bu)同,管(guan)(guan)(guan)道(dao)出現(xian)熱拱(gong)現(xian)象。熱拱(gong)現(xian)象影響了管(guan)(guan)(guan)線的安(an)全狀(zhuang)態(tai),需要配管(guan)(guan)(guan)設計時進(jin)行(xing)設計處理。
對于管(guan)(guan)道(dao)環(huan)(huan)境(jing)溫度(du),有一些參考資料或規范上寫(xie)著20℃。有的工(gong)(gong)程項目按20℃環(huan)(huan)境(jing)溫度(du)評定(ding)管(guan)(guan)道(dao)柔性造(zao)成設(she)計(ji)事故發生。環(huan)(huan)境(jing)溫度(du)在管(guan)(guan)道(dao)應力分析中(zhong)是(shi)個很重(zhong)要的設(she)計(ji)條件(jian),需要根(gen)據工(gong)(gong)程實際情況來確定(ding),一般會用年平均溫度(du)來進行考慮,但是(shi),真正的環(huan)(huan)境(jing)溫度(du)是(shi)指工(gong)(gong)程所在地管(guan)(guan)道(dao)安(an)裝最(zui)后焊縫施工(gong)(gong)時(shi)的環(huan)(huan)境(jing)溫度(du),這樣(yang)就(jiu)可以決定(ding)安(an)裝的初態。
某(mou)管廊框(kuang)架結(jie)(jie)構(gou)的荷載(zai)(zai)條件(jian)設(she)計時,該設(she)計單位管道(dao)專(zhuan)(zhuan)業給(gei)結(jie)(jie)構(gou)專(zhuan)(zhuan)業的垂直荷載(zai)(zai)數據普遍偏大(da)了至少5倍(bei),造成(cheng)結(jie)(jie)構(gou)梁柱比正常粗(cu)大(da)了很多,結(jie)(jie)構(gou)立(li)面水平斜撐(cheng)比正常多了不少。
某(mou)現(xian)場管(guan)線剛投(tou)入試運行幾天,就(jiu)發(fa)(fa)現(xian)管(guan)廊上某(mou)工藝毒性管(guan)線泄(xie)漏(lou),幸虧巡(xun)檢人員(yuan)及時發(fa)(fa)現(xian),未造成嚴重后(hou)果。經(jing)查(cha)發(fa)(fa)現(xian)是(shi)因為(wei)壓力管(guan)道設計(ji)人員(yuan)遺(yi)漏(lou)了自然補償彎設計(ji),運行后(hou)引起管(guan)線彎頭應力超標而裂(lie)縫泄(xie)漏(lou)。
GB 50316《工業金屬管(guan)道(dao)設計規范》、SH 3059《石油(you)化(hua)工管(guan)道(dao)設計器(qi)材選(xuan)用通(tong)則(ze)》HG/T 20645《化(hua)工裝置管(guan)道(dao)機械設計規定(ding)》、ASME B31.3《工藝管(guan)道(dao)》等常用的(de)標準規范詳細介紹(shao)了壓力管(guan)道(dao)元件(jian)的(de)強度計算(suan),包括下列金屬管(guan)道(dao)組成件(jian):金屬直管(guan);彎管(guan)/彎頭及斜接彎頭;三通(tong);盲板與平板封頭;開孔(kong)(支管(guan))補強;蒸汽夾套管(guan)端板等。