有(you)(you)的設計(ji)(ji)人(ren)員(yuan)咨詢浙江至德鋼業有(you)(you)限(xian)公司工(gong)程師(shi)工(gong)業管(guan)道(dao)與輸氣管(guan)道(dao)的壁厚(hou)計(ji)(ji)算是否(fou)可以(yi)統一或者互相替代(dai)使用?因兩者的壁厚(hou)計(ji)(ji)算具有(you)(you)以(yi)下區別,所以(yi)肯(ken)定(ding)是不(bu)能混(hun)用的。



一、工業管(guan)道與輸氣管(guan)道直管(guan)壁厚計算(suan)公式比較


 1. 壁厚(hou)計算理論基礎比較


   承受內壓的(de)直管屬于旋轉殼體的(de)一(yi)種,旋轉殼體應(ying)(ying)(ying)(ying)力(li)(li)(li)(li)分析(xi)理(li)論(lun)有(you)兩類:一(yi)類是忽(hu)略彎矩(ju)的(de)無力(li)(li)(li)(li)矩(ju)理(li)論(lun)一(yi)-薄膜(mo)理(li)論(lun),導出的(de)是壁(bi)厚計(ji)算(suan)的(de)薄膜(mo)應(ying)(ying)(ying)(ying)力(li)(li)(li)(li)公式,該公式計(ji)算(suan)的(de)是沿(yan)(yan)壁(bi)厚均(jun)勻分布(bu)(bu)的(de)兩向應(ying)(ying)(ying)(ying)力(li)(li)(li)(li),即軸向應(ying)(ying)(ying)(ying)力(li)(li)(li)(li)和周向應(ying)(ying)(ying)(ying)力(li)(li)(li)(li),忽(hu)略了徑(jing)(jing)向應(ying)(ying)(ying)(ying)力(li)(li)(li)(li)。另(ling)一(yi)類是彈性(xing)力(li)(li)(li)(li)學(xue)應(ying)(ying)(ying)(ying)力(li)(li)(li)(li)分析(xi)理(li)論(lun)一(yi)一(yi)拉(la)美公式,共(gong)三個方向的(de)應(ying)(ying)(ying)(ying)力(li)(li)(li)(li),周向應(ying)(ying)(ying)(ying)力(li)(li)(li)(li)和徑(jing)(jing)向應(ying)(ying)(ying)(ying)力(li)(li)(li)(li)沿(yan)(yan)壁(bi)厚非線(xian)性(xing)分布(bu)(bu),軸向應(ying)(ying)(ying)(ying)力(li)(li)(li)(li)沿(yan)(yan)壁(bi)厚均(jun)勻分布(bu)(bu)。


   GB 50251《輸氣(qi)(qi)(qi)管道(dao)(dao)工(gong)程(cheng)設計規范》采(cai)用ASME B31.8《輸氣(qi)(qi)(qi)和配(pei)氣(qi)(qi)(qi)管道(dao)(dao)系統》的(de)(de)壁(bi)(bi)厚計算(suan)公(gong)式(shi)(shi),公(gong)式(shi)(shi)源于無力矩(ju)理(li)論(lun)(lun)的(de)(de)薄膜理(li)論(lun)(lun)應力公(gong)式(shi)(shi)。GB/T 20801、GB 50316、SH/T 3059等標準采(cai)用ASME B31.3《工(gong)藝管道(dao)(dao)》的(de)(de)壁(bi)(bi)厚計算(suan)公(gong)式(shi)(shi),公(gong)式(shi)(shi)是拉美(mei)公(gong)式(shi)(shi)的(de)(de)經驗(yan)近(jin)似式(shi)(shi)。輸氣(qi)(qi)(qi)管道(dao)(dao)壁(bi)(bi)厚計算(suan)公(gong)式(shi)(shi)的(de)(de)理(li)論(lun)(lun)基礎采(cai)用無力矩(ju)理(li)論(lun)(lun)-薄膜理(li)論(lun)(lun),而(er)工(gong)業管道(dao)(dao)采(cai)用彈性力學應力分析(xi)理(li)論(lun)(lun)-拉美(mei)公(gong)式(shi)(shi)。


 2. 安全系數取值方式的比較


   輸氣管(guan)(guan)道(dao)(dao)(dao)由于需(xu)穿越城市、村鎮(zhen)等,根據(ju)管(guan)(guan)道(dao)(dao)(dao)通過區域的(de)(de)(de)不同條(tiao)件,采(cai)用(yong)改(gai)變管(guan)(guan)道(dao)(dao)(dao)應力水平(即(ji)改(gai)變管(guan)(guan)道(dao)(dao)(dao)壁厚(hou))以強(qiang)度(du)確保管(guan)(guan)道(dao)(dao)(dao)自身(shen)的(de)(de)(de)安(an)(an)全,為(wei)管(guan)(guan)道(dao)(dao)(dao)周圍環(huan)境提供(gong)安(an)(an)全保障(zhang)(采(cai)用(yong)不同的(de)(de)(de)強(qiang)度(du)設計(ji)(ji)系數F)的(de)(de)(de)理念,同時(shi)也體現了管(guan)(guan)道(dao)(dao)(dao)的(de)(de)(de)經(jing)濟成(cheng)本的(de)(de)(de)合理性。GB50251中規定的(de)(de)(de)強(qiang)度(du)設計(ji)(ji)系數F值(zhi),一級地(di)區為(wei)0.8,四級地(di)區為(wei)0.4。強(qiang)度(du)設計(ji)(ji)系數F值(zhi)的(de)(de)(de)規定與取值(zhi)源自ASME B31.8《輸氣和配(pei)氣管(guan)(guan)道(dao)(dao)(dao)系統》。


   工(gong)業管道壁厚計算(suan)中,設計溫(wen)度下的(de)(de)材(cai)料許(xu)用(yong)(yong)應(ying)(ying)(ying)力(li)(li)由(you)材(cai)料的(de)(de)力(li)(li)學(xue)性能(neng)除以(yi)相應(ying)(ying)(ying)的(de)(de)安(an)全(quan)(quan)(quan)系(xi)(xi)(xi)數(shu)而(er)得(de),GB/T 20801、GB 50316、SH/T 3059規(gui)定的(de)(de)材(cai)料安(an)全(quan)(quan)(quan)系(xi)(xi)(xi)數(shu)與GB 150中材(cai)料安(an)全(quan)(quan)(quan)系(xi)(xi)(xi)數(shu)的(de)(de)要求(qiu)相同(tong)。由(you)于工(gong)業管道處于有(you)限(xian)(xian)(xian)范(fan)圍的(de)(de)工(gong)廠環境(jing)中,材(cai)料的(de)(de)安(an)全(quan)(quan)(quan)系(xi)(xi)(xi)數(shu)根(gen)據(ju)材(cai)料的(de)(de)類型(xing)和力(li)(li)學(xue)性能(neng)(強(qiang)度極(ji)限(xian)(xian)(xian)、屈服極(ji)限(xian)(xian)(xian)、持久強(qiang)度、蠕變極(ji)限(xian)(xian)(xian))的(de)(de)不同(tong)而(er)取(qu)值,按(an)照規(gui)范(fan)規(gui)定選(xuan)取(qu)許(xu)用(yong)(yong)應(ying)(ying)(ying)力(li)(li)值。許(xu)用(yong)(yong)應(ying)(ying)(ying)力(li)(li)值的(de)(de)大小與工(gong)業管道所(suo)處的(de)(de)環境(jing)條件完(wan)全(quan)(quan)(quan)無關(guan),在GB/T20801、GB 50316、SH/T 3059等中規(gui)定使用(yong)(yong)應(ying)(ying)(ying)力(li)(li)表(biao)中的(de)(de)值,既體現了(le)許(xu)用(yong)(yong)應(ying)(ying)(ying)力(li)(li)所(suo)表(biao)達的(de)(de)安(an)全(quan)(quan)(quan)強(qiang)度,又體現了(le)工(gong)程設計的(de)(de)經濟合理性。


   輸(shu)氣管(guan)道(dao)和工業管(guan)道(dao)壁厚(hou)計(ji)算公式中安全系(xi)數的區別,在(zai)安全理念和規(gui)范(fan)內(nei)容上存(cun)在(zai)差異,在(zai)設計(ji)上是無法統(tong)一的。


 3. 鋼管壁(bi)厚附加(jia)裕量的(de)比較(jiao)


   輸(shu)氣管(guan)道在用公式(shi)得出計算壁(bi)厚(hou)之后,圓(yuan)整(zheng)到鋼(gang)管(guan)標準規(gui)定(ding)的(de)(de)壁(bi)厚(hou),一(yi)般(ban)沒有考(kao)慮材料厚(hou)度(du)偏(pian)差和腐(fu)蝕裕量。但是ASME B31.8規(gui)定(ding)采用該(gai)規(gui)范所列鋼(gang)管(guan),已經考(kao)慮了鋼(gang)管(guan)的(de)(de)壁(bi)厚(hou)負偏(pian)差,并且加了裕量,例如,如采用API5L,則不(bu)必再另加厚(hou)度(du)負偏(pian)差了。


  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(guan)材料選用的比較


  由于(yu)輸(shu)(shu)氣(qi)管(guan)(guan)(guan)道距離長,鋼(gang)(gang)(gang)管(guan)(guan)(guan)用(yong)量大,天然氣(qi)輸(shu)(shu)送量大,輸(shu)(shu)氣(qi)管(guan)(guan)(guan)道朝(chao)著高壓力(li)、大直徑方向發展(zhan),鋼(gang)(gang)(gang)管(guan)(guan)(guan)材(cai)料也(ye)朝(chao)著高強度、微合金的(de)(de)(de)(de)方向發展(zhan)。與輸(shu)(shu)氣(qi)管(guan)(guan)(guan)道工(gong)(gong)程相配套的(de)(de)(de)(de)鋼(gang)(gang)(gang)管(guan)(guan)(guan)也(ye)有了自成體系的(de)(de)(de)(de)鋼(gang)(gang)(gang)管(guan)(guan)(guan)標準(zhun)(zhun)(zhun),在(zai)(zai)國(guo)際(ji)上(shang)(shang)得(de)到廣泛應用(yong)的(de)(de)(de)(de)鋼(gang)(gang)(gang)管(guan)(guan)(guan)標準(zhun)(zhun)(zhun)是(shi)(shi)美國(guo)標準(zhun)(zhun)(zhun)API5L。該標準(zhun)(zhun)(zhun)的(de)(de)(de)(de)最高鋼(gang)(gang)(gang)級為L830M(PSL2),規定的(de)(de)(de)(de)屈服強度最小值(zhi)為830 MPa。ISO 3183《石(shi)(shi)油天然氣(qi)工(gong)(gong)業(ye)管(guan)(guan)(guan)線輸(shu)(shu)送系統(tong)(tong)用(yong)鋼(gang)(gang)(gang)管(guan)(guan)(guan)》是(shi)(shi)在(zai)(zai)API5L《管(guan)(guan)(guan)線鋼(gang)(gang)(gang)管(guan)(guan)(guan)規范(fan)(fan)》基礎上(shang)(shang)編(bian)制的(de)(de)(de)(de)。GB/T 9711《石(shi)(shi)油天然氣(qi)工(gong)(gong)業(ye) 管(guan)(guan)(guan)線輸(shu)(shu)送系統(tong)(tong)用(yong)鋼(gang)(gang)(gang)管(guan)(guan)(guan)》是(shi)(shi)在(zai)(zai)ISO 3183標準(zhun)(zhun)(zhun)基礎上(shang)(shang)修改編(bian)制的(de)(de)(de)(de),該標準(zhun)(zhun)(zhun)得(de)到了廣泛應用(yong)。與工(gong)(gong)業(ye)管(guan)(guan)(guan)道用(yong)鋼(gang)(gang)(gang)管(guan)(guan)(guan)在(zai)(zai)技術上(shang)(shang)有重大區別(bie)。GB 50349《氣(qi)田集(ji)輸(shu)(shu)設(she)計規范(fan)(fan)》規定氣(qi)田集(ji)輸(shu)(shu)管(guan)(guan)(guan)道用(yong)鋼(gang)(gang)(gang)管(guan)(guan)(guan)也(ye)是(shi)(shi)選用(yong)GB/T 9711。


  工(gong)(gong)業(ye)管(guan)(guan)道所屬裝置(zhi)的(de)(de)(de)管(guan)(guan)道流體多(duo)樣(yang)(yang)化(hua)、設計參(can)數各不相同,工(gong)(gong)業(ye)管(guan)(guan)道的(de)(de)(de)器材(cai)選用(yong)(yong)(yong)(yong)尚無(wu)(wu)自成(cheng)體系的(de)(de)(de)統一(yi)標(biao)準(zhun),均是(shi)使用(yong)(yong)(yong)(yong)相應的(de)(de)(de)鋼(gang)材(cai)和鋼(gang)管(guan)(guan)標(biao)準(zhun),例(li)如國標(biao)鋼(gang)管(guan)(guan)常用(yong)(yong)(yong)(yong)標(biao)準(zhun):GB/T13793《直縫電焊鋼(gang)管(guan)(guan)》,GB/T9948《石(shi)油裂化(hua)用(yong)(yong)(yong)(yong)無(wu)(wu)縫鋼(gang)管(guan)(guan)》,GB/T 6479《高(gao)壓化(hua)肥設備(bei)用(yong)(yong)(yong)(yong)無(wu)(wu)縫鋼(gang)管(guan)(guan)》,GB/T8163《輸送流體用(yong)(yong)(yong)(yong)無(wu)(wu)縫鋼(gang)管(guan)(guan)》,GB/T3087《低中壓鍋(guo)爐用(yong)(yong)(yong)(yong)無(wu)(wu)縫鋼(gang)管(guan)(guan)》,GB/T5310《高(gao)壓鍋(guo)爐用(yong)(yong)(yong)(yong)無(wu)(wu)縫鋼(gang)管(guan)(guan)》等數十個,工(gong)(gong)業(ye)管(guan)(guan)道器材(cai)選用(yong)(yong)(yong)(yong)具體規定與輸氣(qi)管(guan)(guan)道的(de)(de)(de)材(cai)料要求是(shi)大不一(yi)樣(yang)(yang)的(de)(de)(de),輸氣(qi)管(guan)(guan)道與工(gong)(gong)業(ye)管(guan)(guan)道在材(cai)料選用(yong)(yong)(yong)(yong)及材(cai)料標(biao)準(zhun)上均有很大區別(bie)。



三、管道沖擊試驗的(de)比(bi)較


  輸(shu)氣(qi)管(guan)(guan)道(包括(kuo)輸(shu)氣(qi)站)一(yi)般都在野外,受自然環境(jing)(低(di)(di)(di)溫(wen))的(de)(de)影響比較(jiao)大,輸(shu)氣(qi)管(guan)(guan)道用鋼管(guan)(guan)對(dui)低(di)(di)(di)溫(wen)沖(chong)擊韌性(xing)的(de)(de)要(yao)求(qiu)較(jiao)高(gao),以防止鋼管(guan)(guan)脆性(xing)斷(duan)裂擴(kuo)展(zhan)(zhan)和(he)控制延性(xing)斷(duan)裂擴(kuo)展(zhan)(zhan)。我(wo)國對(dui)干線和(he)站場用鋼管(guan)(guan)提出了在API5L的(de)(de)基(ji)礎上對(dui)鋼管(guan)(guan)和(he)焊縫(feng)進行夏(xia)比沖(chong)擊試驗的(de)(de)要(yao)求(qiu),規定(ding)其試驗溫(wen)度應低(di)(di)(di)于管(guan)(guan)道通過當地的(de)(de)最(zui)低(di)(di)(di)環境(jing)溫(wen)度,一(yi)般取-10℃,-20℃、-30℃,夏(xia)比沖(chong)擊韌性(xing)合格值(zhi)根據不(bu)同鋼級和(he)管(guan)(guan)徑分別為27J、40J、54J、80J(3個試樣(yang)最(zui)小(xiao)平均值(zhi))。


  工業管道(dao)對(dui)管道(dao)設計溫度(du)≤-20℃而高于鋼(gang)材使用溫度(du)下限的(de)(de)碳(tan)素(su)鋼(gang)、低(di)合金鋼(gang)、中合金鋼(gang)和(he)高合金鐵素(su)體鋼(gang),要求(qiu)進行夏(xia)比低(di)溫沖擊(ji)試(shi)(shi)驗(yan),試(shi)(shi)驗(yan)沖擊(ji)功合格值根據不同的(de)(de)鋼(gang)材分別為18J、20J、27J、31J(3個試(shi)(shi)樣平(ping)均值),GB/T 20801、GB/T 50316、SH/T 3059等標注中均有明確規定(ding)。


  輸氣管道(dao)與工業管道(dao)設計規范對鋼管提出了夏比低(di)溫沖擊試驗(yan)的要求,在(zai)夏比低(di)溫沖擊試驗(yan)的試驗(yan)溫度(du)與合格值上差(cha)異較大。






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