有的(de)設計(ji)人員(yuan)咨(zi)詢浙江至德鋼業有限公司工程師工業管道(dao)與輸(shu)氣管道(dao)的(de)壁(bi)(bi)厚(hou)(hou)計(ji)算是(shi)否可以統一或(huo)者互(hu)相(xiang)替代(dai)使用(yong)?因兩者的(de)壁(bi)(bi)厚(hou)(hou)計(ji)算具有以下(xia)區別,所以肯定是(shi)不(bu)能混用(yong)的(de)。



一、工業管道(dao)與輸氣管道(dao)直管壁厚(hou)計(ji)算公(gong)式(shi)比較(jiao)


 1. 壁(bi)厚計(ji)算(suan)理(li)論基礎比較


   承(cheng)受內壓的(de)(de)直管屬于旋轉殼體的(de)(de)一(yi)種(zhong),旋轉殼體應(ying)(ying)(ying)力(li)分(fen)析理論(lun)有兩(liang)類:一(yi)類是(shi)忽(hu)略(lve)彎矩的(de)(de)無力(li)矩理論(lun)一(yi)-薄(bo)膜理論(lun),導出(chu)的(de)(de)是(shi)壁(bi)(bi)厚(hou)(hou)計(ji)算的(de)(de)薄(bo)膜應(ying)(ying)(ying)力(li)公式(shi),該(gai)公式(shi)計(ji)算的(de)(de)是(shi)沿壁(bi)(bi)厚(hou)(hou)均(jun)勻分(fen)布的(de)(de)兩(liang)向(xiang)(xiang)(xiang)(xiang)(xiang)應(ying)(ying)(ying)力(li),即軸向(xiang)(xiang)(xiang)(xiang)(xiang)應(ying)(ying)(ying)力(li)和周向(xiang)(xiang)(xiang)(xiang)(xiang)應(ying)(ying)(ying)力(li),忽(hu)略(lve)了徑向(xiang)(xiang)(xiang)(xiang)(xiang)應(ying)(ying)(ying)力(li)。另(ling)一(yi)類是(shi)彈(dan)性力(li)學應(ying)(ying)(ying)力(li)分(fen)析理論(lun)一(yi)一(yi)拉美公式(shi),共三個方向(xiang)(xiang)(xiang)(xiang)(xiang)的(de)(de)應(ying)(ying)(ying)力(li),周向(xiang)(xiang)(xiang)(xiang)(xiang)應(ying)(ying)(ying)力(li)和徑向(xiang)(xiang)(xiang)(xiang)(xiang)應(ying)(ying)(ying)力(li)沿壁(bi)(bi)厚(hou)(hou)非線(xian)性分(fen)布,軸向(xiang)(xiang)(xiang)(xiang)(xiang)應(ying)(ying)(ying)力(li)沿壁(bi)(bi)厚(hou)(hou)均(jun)勻分(fen)布。


   GB 50251《輸(shu)氣(qi)管(guan)道(dao)(dao)工(gong)程(cheng)設計規范(fan)》采用(yong)(yong)(yong)ASME B31.8《輸(shu)氣(qi)和配氣(qi)管(guan)道(dao)(dao)系統》的(de)壁厚計算公式(shi)(shi),公式(shi)(shi)源于無(wu)力(li)矩理(li)(li)論(lun)(lun)的(de)薄膜理(li)(li)論(lun)(lun)應力(li)公式(shi)(shi)。GB/T 20801、GB 50316、SH/T 3059等標準采用(yong)(yong)(yong)ASME B31.3《工(gong)藝管(guan)道(dao)(dao)》的(de)壁厚計算公式(shi)(shi),公式(shi)(shi)是拉(la)美(mei)公式(shi)(shi)的(de)經驗近似式(shi)(shi)。輸(shu)氣(qi)管(guan)道(dao)(dao)壁厚計算公式(shi)(shi)的(de)理(li)(li)論(lun)(lun)基(ji)礎采用(yong)(yong)(yong)無(wu)力(li)矩理(li)(li)論(lun)(lun)-薄膜理(li)(li)論(lun)(lun),而工(gong)業(ye)管(guan)道(dao)(dao)采用(yong)(yong)(yong)彈性力(li)學應力(li)分析理(li)(li)論(lun)(lun)-拉(la)美(mei)公式(shi)(shi)。


 2. 安全系數取(qu)值方式的比(bi)較(jiao)


   輸氣(qi)(qi)(qi)管(guan)道由(you)于需穿越城市、村鎮等,根據管(guan)道通(tong)過區域的(de)(de)不同(tong)條件(jian),采用改變管(guan)道應力水(shui)平(即改變管(guan)道壁厚)以強(qiang)度確保(bao)管(guan)道自(zi)身的(de)(de)安全,為(wei)管(guan)道周圍環境提供安全保(bao)障(采用不同(tong)的(de)(de)強(qiang)度設計(ji)(ji)系數(shu)F)的(de)(de)理(li)念,同(tong)時也體(ti)現(xian)了管(guan)道的(de)(de)經(jing)濟成本的(de)(de)合(he)理(li)性(xing)。GB50251中(zhong)規(gui)定的(de)(de)強(qiang)度設計(ji)(ji)系數(shu)F值,一級地區為(wei)0.8,四(si)級地區為(wei)0.4。強(qiang)度設計(ji)(ji)系數(shu)F值的(de)(de)規(gui)定與取值源(yuan)自(zi)ASME B31.8《輸氣(qi)(qi)(qi)和配氣(qi)(qi)(qi)管(guan)道系統》。


   工(gong)(gong)業(ye)管(guan)道壁(bi)厚計算(suan)中(zhong)(zhong),設(she)計溫(wen)度(du)下的(de)(de)(de)(de)材(cai)(cai)(cai)料(liao)許用應(ying)(ying)(ying)力(li)由材(cai)(cai)(cai)料(liao)的(de)(de)(de)(de)力(li)學性能除(chu)以相應(ying)(ying)(ying)的(de)(de)(de)(de)安(an)全(quan)系數(shu)(shu)而(er)得,GB/T 20801、GB 50316、SH/T 3059規(gui)(gui)(gui)定的(de)(de)(de)(de)材(cai)(cai)(cai)料(liao)安(an)全(quan)系數(shu)(shu)與GB 150中(zhong)(zhong)材(cai)(cai)(cai)料(liao)安(an)全(quan)系數(shu)(shu)的(de)(de)(de)(de)要求相同。由于(yu)工(gong)(gong)業(ye)管(guan)道處(chu)于(yu)有限范圍的(de)(de)(de)(de)工(gong)(gong)廠環(huan)境中(zhong)(zhong),材(cai)(cai)(cai)料(liao)的(de)(de)(de)(de)安(an)全(quan)系數(shu)(shu)根據材(cai)(cai)(cai)料(liao)的(de)(de)(de)(de)類(lei)型和力(li)學性能(強度(du)極(ji)(ji)限、屈服極(ji)(ji)限、持久強度(du)、蠕(ru)變極(ji)(ji)限)的(de)(de)(de)(de)不同而(er)取值(zhi)(zhi)(zhi)(zhi),按照規(gui)(gui)(gui)范規(gui)(gui)(gui)定選取許用應(ying)(ying)(ying)力(li)值(zhi)(zhi)(zhi)(zhi)。許用應(ying)(ying)(ying)力(li)值(zhi)(zhi)(zhi)(zhi)的(de)(de)(de)(de)大小與工(gong)(gong)業(ye)管(guan)道所處(chu)的(de)(de)(de)(de)環(huan)境條件完全(quan)無關,在GB/T20801、GB 50316、SH/T 3059等中(zhong)(zhong)規(gui)(gui)(gui)定使(shi)用應(ying)(ying)(ying)力(li)表(biao)中(zhong)(zhong)的(de)(de)(de)(de)值(zhi)(zhi)(zhi)(zhi),既體現(xian)了許用應(ying)(ying)(ying)力(li)所表(biao)達的(de)(de)(de)(de)安(an)全(quan)強度(du),又體現(xian)了工(gong)(gong)程(cheng)設(she)計的(de)(de)(de)(de)經濟合理(li)性。


   輸氣(qi)管(guan)(guan)道(dao)和工業管(guan)(guan)道(dao)壁厚計算(suan)公式(shi)中(zhong)安(an)全系數的區別,在(zai)安(an)全理念(nian)和規(gui)范內容上存在(zai)差異,在(zai)設(she)計上是無法統一(yi)的。


 3. 鋼(gang)管壁厚(hou)附加裕量(liang)的比(bi)較


   輸氣管(guan)(guan)(guan)道在用公式得出計(ji)算壁厚之后,圓整到鋼(gang)(gang)管(guan)(guan)(guan)標準規定(ding)的壁厚,一般沒有考(kao)慮材料厚度偏(pian)差和腐蝕(shi)裕量。但是(shi)ASME B31.8規定(ding)采用該(gai)規范所(suo)列鋼(gang)(gang)管(guan)(guan)(guan),已經考(kao)慮了(le)(le)鋼(gang)(gang)管(guan)(guan)(guan)的壁厚負偏(pian)差,并且(qie)加了(le)(le)裕量,例(li)如(ru)(ru),如(ru)(ru)采用API5L,則不必再另加厚度負偏(pian)差了(le)(le)。


  工業管道的壁厚計算公式中則明確規定了應該考慮厚度減薄附加量C1和腐蝕磨蝕附加量C2



二、鋼管材料選用的(de)比較


  由于輸(shu)(shu)氣(qi)(qi)管(guan)(guan)道(dao)距離長(chang),鋼(gang)(gang)(gang)管(guan)(guan)用(yong)量大,天(tian)然(ran)氣(qi)(qi)輸(shu)(shu)送量大,輸(shu)(shu)氣(qi)(qi)管(guan)(guan)道(dao)朝(chao)著(zhu)(zhu)高壓力、大直徑方向發(fa)展(zhan)(zhan),鋼(gang)(gang)(gang)管(guan)(guan)材(cai)料(liao)也朝(chao)著(zhu)(zhu)高強度、微合金的(de)(de)(de)方向發(fa)展(zhan)(zhan)。與輸(shu)(shu)氣(qi)(qi)管(guan)(guan)道(dao)工程相配套的(de)(de)(de)鋼(gang)(gang)(gang)管(guan)(guan)也有(you)了自(zi)成(cheng)體系的(de)(de)(de)鋼(gang)(gang)(gang)管(guan)(guan)標(biao)(biao)準(zhun),在(zai)國際(ji)上(shang)得到廣泛應用(yong)的(de)(de)(de)鋼(gang)(gang)(gang)管(guan)(guan)標(biao)(biao)準(zhun)是(shi)(shi)(shi)(shi)美國標(biao)(biao)準(zhun)API5L。該標(biao)(biao)準(zhun)的(de)(de)(de)最(zui)高鋼(gang)(gang)(gang)級為(wei)L830M(PSL2),規(gui)(gui)定的(de)(de)(de)屈服強度最(zui)小值為(wei)830 MPa。ISO 3183《石(shi)油天(tian)然(ran)氣(qi)(qi)工業管(guan)(guan)線(xian)輸(shu)(shu)送系統(tong)(tong)用(yong)鋼(gang)(gang)(gang)管(guan)(guan)》是(shi)(shi)(shi)(shi)在(zai)API5L《管(guan)(guan)線(xian)鋼(gang)(gang)(gang)管(guan)(guan)規(gui)(gui)范》基礎上(shang)編(bian)制的(de)(de)(de)。GB/T 9711《石(shi)油天(tian)然(ran)氣(qi)(qi)工業 管(guan)(guan)線(xian)輸(shu)(shu)送系統(tong)(tong)用(yong)鋼(gang)(gang)(gang)管(guan)(guan)》是(shi)(shi)(shi)(shi)在(zai)ISO 3183標(biao)(biao)準(zhun)基礎上(shang)修改編(bian)制的(de)(de)(de),該標(biao)(biao)準(zhun)得到了廣泛應用(yong)。與工業管(guan)(guan)道(dao)用(yong)鋼(gang)(gang)(gang)管(guan)(guan)在(zai)技術上(shang)有(you)重大區別(bie)。GB 50349《氣(qi)(qi)田(tian)集輸(shu)(shu)設計規(gui)(gui)范》規(gui)(gui)定氣(qi)(qi)田(tian)集輸(shu)(shu)管(guan)(guan)道(dao)用(yong)鋼(gang)(gang)(gang)管(guan)(guan)也是(shi)(shi)(shi)(shi)選用(yong)GB/T 9711。


  工(gong)(gong)業(ye)(ye)(ye)管(guan)(guan)(guan)(guan)(guan)道(dao)所屬(shu)裝置的管(guan)(guan)(guan)(guan)(guan)道(dao)流體(ti)多樣化、設計參數(shu)各不相同,工(gong)(gong)業(ye)(ye)(ye)管(guan)(guan)(guan)(guan)(guan)道(dao)的器(qi)材(cai)(cai)選用(yong)(yong)尚無自成(cheng)體(ti)系的統一(yi)標(biao)準(zhun)(zhun),均是使用(yong)(yong)相應的鋼材(cai)(cai)和鋼管(guan)(guan)(guan)(guan)(guan)標(biao)準(zhun)(zhun),例如國(guo)標(biao)鋼管(guan)(guan)(guan)(guan)(guan)常用(yong)(yong)標(biao)準(zhun)(zhun):GB/T13793《直(zhi)縫(feng)(feng)電焊鋼管(guan)(guan)(guan)(guan)(guan)》,GB/T9948《石油裂(lie)化用(yong)(yong)無縫(feng)(feng)鋼管(guan)(guan)(guan)(guan)(guan)》,GB/T 6479《高壓化肥設備用(yong)(yong)無縫(feng)(feng)鋼管(guan)(guan)(guan)(guan)(guan)》,GB/T8163《輸送(song)流體(ti)用(yong)(yong)無縫(feng)(feng)鋼管(guan)(guan)(guan)(guan)(guan)》,GB/T3087《低中(zhong)壓鍋爐用(yong)(yong)無縫(feng)(feng)鋼管(guan)(guan)(guan)(guan)(guan)》,GB/T5310《高壓鍋爐用(yong)(yong)無縫(feng)(feng)鋼管(guan)(guan)(guan)(guan)(guan)》等數(shu)十個,工(gong)(gong)業(ye)(ye)(ye)管(guan)(guan)(guan)(guan)(guan)道(dao)器(qi)材(cai)(cai)選用(yong)(yong)具體(ti)規定與輸氣管(guan)(guan)(guan)(guan)(guan)道(dao)的材(cai)(cai)料要求是大(da)不一(yi)樣的,輸氣管(guan)(guan)(guan)(guan)(guan)道(dao)與工(gong)(gong)業(ye)(ye)(ye)管(guan)(guan)(guan)(guan)(guan)道(dao)在(zai)材(cai)(cai)料選用(yong)(yong)及材(cai)(cai)料標(biao)準(zhun)(zhun)上(shang)均有很大(da)區別。



三、管道(dao)沖擊試驗的比較


  輸氣(qi)(qi)管(guan)(guan)(guan)道(包括(kuo)輸氣(qi)(qi)站)一般都在野(ye)外,受自然環境(jing)(低(di)溫(wen))的(de)影響比(bi)較大,輸氣(qi)(qi)管(guan)(guan)(guan)道用(yong)鋼(gang)管(guan)(guan)(guan)對低(di)溫(wen)沖擊韌性的(de)要(yao)求(qiu)較高,以防(fang)止(zhi)鋼(gang)管(guan)(guan)(guan)脆性斷(duan)裂擴(kuo)展和控制(zhi)延性斷(duan)裂擴(kuo)展。我國對干線(xian)和站場用(yong)鋼(gang)管(guan)(guan)(guan)提(ti)出(chu)了在API5L的(de)基礎(chu)上對鋼(gang)管(guan)(guan)(guan)和焊縫進行夏比(bi)沖擊試(shi)驗的(de)要(yao)求(qiu),規定其試(shi)驗溫(wen)度應低(di)于管(guan)(guan)(guan)道通過(guo)當地的(de)最低(di)環境(jing)溫(wen)度,一般取(qu)-10℃,-20℃、-30℃,夏比(bi)沖擊韌性合(he)格值根(gen)據不同鋼(gang)級和管(guan)(guan)(guan)徑(jing)分(fen)別(bie)為(wei)27J、40J、54J、80J(3個(ge)試(shi)樣(yang)最小(xiao)平(ping)均(jun)值)。


  工業(ye)管道對管道設計溫度(du)≤-20℃而(er)高(gao)于鋼材(cai)使用(yong)溫度(du)下限的(de)碳素鋼、低合金(jin)鋼、中合金(jin)鋼和高(gao)合金(jin)鐵素體鋼,要求進(jin)行夏比低溫沖(chong)擊(ji)試(shi)(shi)驗(yan),試(shi)(shi)驗(yan)沖(chong)擊(ji)功合格值根據(ju)不同的(de)鋼材(cai)分別為(wei)18J、20J、27J、31J(3個試(shi)(shi)樣平均(jun)值),GB/T 20801、GB/T 50316、SH/T 3059等(deng)標注(zhu)中均(jun)有明確規定。


  輸氣管(guan)道與(yu)工業(ye)管(guan)道設計規范對鋼管(guan)提出(chu)了夏(xia)比(bi)低(di)溫(wen)(wen)沖擊試(shi)驗(yan)的要求,在夏(xia)比(bi)低(di)溫(wen)(wen)沖擊試(shi)驗(yan)的試(shi)驗(yan)溫(wen)(wen)度與(yu)合格值上差異較大(da)。






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