有(you)的(de)設計人員咨詢浙江至(zhi)德鋼業有(you)限公(gong)司工程師工業管(guan)道與(yu)輸氣(qi)管(guan)道的(de)壁(bi)厚(hou)計算(suan)是否可以統一或者互相替代(dai)使用?因兩者的(de)壁(bi)厚(hou)計算(suan)具有(you)以下區別,所以肯定(ding)是不能混用的(de)。



一、工業(ye)管(guan)道與(yu)輸(shu)氣(qi)管(guan)道直管(guan)壁厚計算公式比(bi)較


 1. 壁厚計算理論基礎比較(jiao)


   承受內(nei)壓的(de)直(zhi)管(guan)屬于旋轉(zhuan)殼體的(de)一(yi)(yi)種(zhong),旋轉(zhuan)殼體應(ying)(ying)力(li)(li)(li)分(fen)(fen)析理(li)論有兩(liang)類:一(yi)(yi)類是(shi)(shi)忽略(lve)彎(wan)矩的(de)無力(li)(li)(li)矩理(li)論一(yi)(yi)-薄(bo)膜(mo)理(li)論,導出的(de)是(shi)(shi)壁(bi)厚(hou)計算的(de)薄(bo)膜(mo)應(ying)(ying)力(li)(li)(li)公(gong)式,該公(gong)式計算的(de)是(shi)(shi)沿壁(bi)厚(hou)均勻分(fen)(fen)布的(de)兩(liang)向(xiang)應(ying)(ying)力(li)(li)(li),即(ji)軸向(xiang)應(ying)(ying)力(li)(li)(li)和(he)周(zhou)向(xiang)應(ying)(ying)力(li)(li)(li),忽略(lve)了徑(jing)向(xiang)應(ying)(ying)力(li)(li)(li)。另一(yi)(yi)類是(shi)(shi)彈性(xing)力(li)(li)(li)學(xue)應(ying)(ying)力(li)(li)(li)分(fen)(fen)析理(li)論一(yi)(yi)一(yi)(yi)拉美(mei)公(gong)式,共三個方向(xiang)的(de)應(ying)(ying)力(li)(li)(li),周(zhou)向(xiang)應(ying)(ying)力(li)(li)(li)和(he)徑(jing)向(xiang)應(ying)(ying)力(li)(li)(li)沿壁(bi)厚(hou)非線性(xing)分(fen)(fen)布,軸向(xiang)應(ying)(ying)力(li)(li)(li)沿壁(bi)厚(hou)均勻分(fen)(fen)布。


   GB 50251《輸(shu)氣管(guan)(guan)道(dao)(dao)工(gong)程設(she)計(ji)規范》采用(yong)ASME B31.8《輸(shu)氣和配氣管(guan)(guan)道(dao)(dao)系統(tong)》的壁(bi)厚(hou)計(ji)算公(gong)(gong)(gong)式(shi)(shi),公(gong)(gong)(gong)式(shi)(shi)源于(yu)無力(li)矩(ju)理(li)論(lun)的薄膜(mo)理(li)論(lun)應力(li)公(gong)(gong)(gong)式(shi)(shi)。GB/T 20801、GB 50316、SH/T 3059等標準采用(yong)ASME B31.3《工(gong)藝(yi)管(guan)(guan)道(dao)(dao)》的壁(bi)厚(hou)計(ji)算公(gong)(gong)(gong)式(shi)(shi),公(gong)(gong)(gong)式(shi)(shi)是拉美公(gong)(gong)(gong)式(shi)(shi)的經驗(yan)近似式(shi)(shi)。輸(shu)氣管(guan)(guan)道(dao)(dao)壁(bi)厚(hou)計(ji)算公(gong)(gong)(gong)式(shi)(shi)的理(li)論(lun)基礎采用(yong)無力(li)矩(ju)理(li)論(lun)-薄膜(mo)理(li)論(lun),而工(gong)業管(guan)(guan)道(dao)(dao)采用(yong)彈性(xing)力(li)學(xue)應力(li)分析理(li)論(lun)-拉美公(gong)(gong)(gong)式(shi)(shi)。


 2. 安全系數取值方(fang)式的比較


   輸氣管(guan)(guan)道(dao)由于需穿越(yue)城(cheng)市、村(cun)鎮等,根據管(guan)(guan)道(dao)通過區(qu)域(yu)的(de)不同條件,采(cai)用改變管(guan)(guan)道(dao)應力(li)水平(即(ji)改變管(guan)(guan)道(dao)壁厚(hou))以強度(du)確保管(guan)(guan)道(dao)自身(shen)的(de)安全,為(wei)管(guan)(guan)道(dao)周圍環境(jing)提(ti)供安全保障(采(cai)用不同的(de)強度(du)設(she)(she)計系(xi)數F)的(de)理念,同時也體現了管(guan)(guan)道(dao)的(de)經濟成(cheng)本的(de)合理性。GB50251中(zhong)規定(ding)的(de)強度(du)設(she)(she)計系(xi)數F值(zhi)(zhi),一級(ji)地區(qu)為(wei)0.8,四級(ji)地區(qu)為(wei)0.4。強度(du)設(she)(she)計系(xi)數F值(zhi)(zhi)的(de)規定(ding)與取值(zhi)(zhi)源自ASME B31.8《輸氣和配氣管(guan)(guan)道(dao)系(xi)統》。


   工(gong)(gong)(gong)(gong)(gong)業管(guan)道(dao)壁厚計算中,設計溫度(du)下的(de)(de)(de)(de)(de)材(cai)料(liao)(liao)(liao)許(xu)用(yong)(yong)應(ying)(ying)力由(you)材(cai)料(liao)(liao)(liao)的(de)(de)(de)(de)(de)力學性能(neng)除以相應(ying)(ying)的(de)(de)(de)(de)(de)安全(quan)系(xi)數(shu)而得,GB/T 20801、GB 50316、SH/T 3059規(gui)定(ding)的(de)(de)(de)(de)(de)材(cai)料(liao)(liao)(liao)安全(quan)系(xi)數(shu)與(yu)GB 150中材(cai)料(liao)(liao)(liao)安全(quan)系(xi)數(shu)的(de)(de)(de)(de)(de)要求相同。由(you)于(yu)工(gong)(gong)(gong)(gong)(gong)業管(guan)道(dao)處(chu)(chu)于(yu)有(you)限(xian)(xian)范圍的(de)(de)(de)(de)(de)工(gong)(gong)(gong)(gong)(gong)廠環(huan)境(jing)中,材(cai)料(liao)(liao)(liao)的(de)(de)(de)(de)(de)安全(quan)系(xi)數(shu)根據材(cai)料(liao)(liao)(liao)的(de)(de)(de)(de)(de)類型和力學性能(neng)(強度(du)極限(xian)(xian)、屈(qu)服極限(xian)(xian)、持久強度(du)、蠕變極限(xian)(xian))的(de)(de)(de)(de)(de)不同而取值,按照規(gui)范規(gui)定(ding)選(xuan)取許(xu)用(yong)(yong)應(ying)(ying)力值。許(xu)用(yong)(yong)應(ying)(ying)力值的(de)(de)(de)(de)(de)大小與(yu)工(gong)(gong)(gong)(gong)(gong)業管(guan)道(dao)所處(chu)(chu)的(de)(de)(de)(de)(de)環(huan)境(jing)條件完全(quan)無(wu)關,在GB/T20801、GB 50316、SH/T 3059等(deng)中規(gui)定(ding)使用(yong)(yong)應(ying)(ying)力表中的(de)(de)(de)(de)(de)值,既體現了許(xu)用(yong)(yong)應(ying)(ying)力所表達的(de)(de)(de)(de)(de)安全(quan)強度(du),又體現了工(gong)(gong)(gong)(gong)(gong)程設計的(de)(de)(de)(de)(de)經濟合理性。


   輸氣管道和(he)工業(ye)管道壁厚(hou)計算公式中(zhong)安全(quan)系數(shu)的區別,在(zai)安全(quan)理念和(he)規范內(nei)容上存(cun)在(zai)差異,在(zai)設(she)計上是(shi)無法統(tong)一的。


 3. 鋼(gang)管(guan)壁(bi)厚(hou)附加裕量的(de)比較


   輸氣管(guan)道在用(yong)(yong)公(gong)式(shi)得(de)出計算壁(bi)(bi)厚(hou)之后,圓整到鋼(gang)管(guan)標(biao)準規定的壁(bi)(bi)厚(hou),一般沒有(you)考慮材(cai)料厚(hou)度偏差和腐(fu)蝕裕量。但是ASME B31.8規定采用(yong)(yong)該(gai)規范所列鋼(gang)管(guan),已(yi)經(jing)考慮了鋼(gang)管(guan)的壁(bi)(bi)厚(hou)負偏差,并(bing)且加了裕量,例如,如采用(yong)(yong)API5L,則不必再(zai)另加厚(hou)度負偏差了。


  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、鋼管材料(liao)選(xuan)用的比較


  由于輸(shu)氣(qi)管(guan)(guan)道(dao)距離長,鋼(gang)(gang)(gang)(gang)(gang)(gang)管(guan)(guan)用(yong)(yong)量(liang)大(da),天然(ran)氣(qi)輸(shu)送量(liang)大(da),輸(shu)氣(qi)管(guan)(guan)道(dao)朝(chao)著(zhu)高(gao)壓力、大(da)直徑(jing)方向發展,鋼(gang)(gang)(gang)(gang)(gang)(gang)管(guan)(guan)材料也(ye)朝(chao)著(zhu)高(gao)強度、微合(he)金的(de)(de)方向發展。與輸(shu)氣(qi)管(guan)(guan)道(dao)工(gong)程(cheng)相配(pei)套的(de)(de)鋼(gang)(gang)(gang)(gang)(gang)(gang)管(guan)(guan)也(ye)有了自成體(ti)系的(de)(de)鋼(gang)(gang)(gang)(gang)(gang)(gang)管(guan)(guan)標(biao)準,在國際上得(de)到廣泛應用(yong)(yong)的(de)(de)鋼(gang)(gang)(gang)(gang)(gang)(gang)管(guan)(guan)標(biao)準是美(mei)國標(biao)準API5L。該標(biao)準的(de)(de)最高(gao)鋼(gang)(gang)(gang)(gang)(gang)(gang)級為L830M(PSL2),規(gui)定的(de)(de)屈服(fu)強度最小值(zhi)為830 MPa。ISO 3183《石(shi)油天然(ran)氣(qi)工(gong)業管(guan)(guan)線輸(shu)送系統用(yong)(yong)鋼(gang)(gang)(gang)(gang)(gang)(gang)管(guan)(guan)》是在API5L《管(guan)(guan)線鋼(gang)(gang)(gang)(gang)(gang)(gang)管(guan)(guan)規(gui)范(fan)》基礎上編制的(de)(de)。GB/T 9711《石(shi)油天然(ran)氣(qi)工(gong)業 管(guan)(guan)線輸(shu)送系統用(yong)(yong)鋼(gang)(gang)(gang)(gang)(gang)(gang)管(guan)(guan)》是在ISO 3183標(biao)準基礎上修改(gai)編制的(de)(de),該標(biao)準得(de)到了廣泛應用(yong)(yong)。與工(gong)業管(guan)(guan)道(dao)用(yong)(yong)鋼(gang)(gang)(gang)(gang)(gang)(gang)管(guan)(guan)在技(ji)術上有重(zhong)大(da)區別(bie)。GB 50349《氣(qi)田(tian)(tian)集輸(shu)設計(ji)規(gui)范(fan)》規(gui)定氣(qi)田(tian)(tian)集輸(shu)管(guan)(guan)道(dao)用(yong)(yong)鋼(gang)(gang)(gang)(gang)(gang)(gang)管(guan)(guan)也(ye)是選用(yong)(yong)GB/T 9711。


  工(gong)業管(guan)(guan)(guan)(guan)道(dao)(dao)所屬裝置的(de)(de)管(guan)(guan)(guan)(guan)道(dao)(dao)流體(ti)多樣化、設計參(can)數(shu)各(ge)不相同(tong),工(gong)業管(guan)(guan)(guan)(guan)道(dao)(dao)的(de)(de)器(qi)材(cai)(cai)選(xuan)用(yong)(yong)(yong)(yong)尚無(wu)(wu)自成(cheng)體(ti)系的(de)(de)統一(yi)標(biao)(biao)(biao)準(zhun),均是(shi)使用(yong)(yong)(yong)(yong)相應的(de)(de)鋼(gang)材(cai)(cai)和鋼(gang)管(guan)(guan)(guan)(guan)標(biao)(biao)(biao)準(zhun),例如國標(biao)(biao)(biao)鋼(gang)管(guan)(guan)(guan)(guan)常用(yong)(yong)(yong)(yong)標(biao)(biao)(biao)準(zhun):GB/T13793《直縫(feng)(feng)(feng)電(dian)焊鋼(gang)管(guan)(guan)(guan)(guan)》,GB/T9948《石油(you)裂化用(yong)(yong)(yong)(yong)無(wu)(wu)縫(feng)(feng)(feng)鋼(gang)管(guan)(guan)(guan)(guan)》,GB/T 6479《高(gao)壓化肥設備用(yong)(yong)(yong)(yong)無(wu)(wu)縫(feng)(feng)(feng)鋼(gang)管(guan)(guan)(guan)(guan)》,GB/T8163《輸送(song)流體(ti)用(yong)(yong)(yong)(yong)無(wu)(wu)縫(feng)(feng)(feng)鋼(gang)管(guan)(guan)(guan)(guan)》,GB/T3087《低中(zhong)壓鍋爐用(yong)(yong)(yong)(yong)無(wu)(wu)縫(feng)(feng)(feng)鋼(gang)管(guan)(guan)(guan)(guan)》,GB/T5310《高(gao)壓鍋爐用(yong)(yong)(yong)(yong)無(wu)(wu)縫(feng)(feng)(feng)鋼(gang)管(guan)(guan)(guan)(guan)》等數(shu)十個(ge),工(gong)業管(guan)(guan)(guan)(guan)道(dao)(dao)器(qi)材(cai)(cai)選(xuan)用(yong)(yong)(yong)(yong)具體(ti)規定與(yu)輸氣管(guan)(guan)(guan)(guan)道(dao)(dao)的(de)(de)材(cai)(cai)料(liao)(liao)(liao)要求是(shi)大不一(yi)樣的(de)(de),輸氣管(guan)(guan)(guan)(guan)道(dao)(dao)與(yu)工(gong)業管(guan)(guan)(guan)(guan)道(dao)(dao)在材(cai)(cai)料(liao)(liao)(liao)選(xuan)用(yong)(yong)(yong)(yong)及材(cai)(cai)料(liao)(liao)(liao)標(biao)(biao)(biao)準(zhun)上均有(you)很大區別(bie)。



三、管道沖(chong)擊(ji)試(shi)驗的比較


  輸氣(qi)管(guan)(guan)道(dao)(包括輸氣(qi)站)一般(ban)都(dou)在野(ye)外,受(shou)自(zi)然環境(低(di)溫(wen))的(de)影響比較大,輸氣(qi)管(guan)(guan)道(dao)用鋼(gang)(gang)(gang)管(guan)(guan)對低(di)溫(wen)沖擊(ji)韌性的(de)要(yao)求(qiu)較高,以防止鋼(gang)(gang)(gang)管(guan)(guan)脆(cui)性斷裂擴展和(he)控制延性斷裂擴展。我國對干線(xian)和(he)站場(chang)用鋼(gang)(gang)(gang)管(guan)(guan)提(ti)出了在API5L的(de)基礎上對鋼(gang)(gang)(gang)管(guan)(guan)和(he)焊縫進行夏比沖擊(ji)試驗的(de)要(yao)求(qiu),規(gui)定其試驗溫(wen)度(du)應低(di)于(yu)管(guan)(guan)道(dao)通(tong)過當地(di)的(de)最(zui)低(di)環境溫(wen)度(du),一般(ban)取-10℃,-20℃、-30℃,夏比沖擊(ji)韌性合格值根據不(bu)同鋼(gang)(gang)(gang)級和(he)管(guan)(guan)徑分別為27J、40J、54J、80J(3個試樣最(zui)小(xiao)平均值)。


  工(gong)業(ye)管道對管道設(she)計溫度≤-20℃而高于鋼(gang)(gang)(gang)材使(shi)用溫度下限的碳素鋼(gang)(gang)(gang)、低合(he)(he)金(jin)鋼(gang)(gang)(gang)、中(zhong)合(he)(he)金(jin)鋼(gang)(gang)(gang)和高合(he)(he)金(jin)鐵(tie)素體鋼(gang)(gang)(gang),要(yao)求進行(xing)夏比低溫沖擊試驗,試驗沖擊功(gong)合(he)(he)格(ge)值根(gen)據不同的鋼(gang)(gang)(gang)材分別為18J、20J、27J、31J(3個(ge)試樣平均值),GB/T 20801、GB/T 50316、SH/T 3059等標注中(zhong)均有明確規(gui)定。


  輸氣管道(dao)與(yu)工(gong)業(ye)管道(dao)設計規(gui)范對鋼(gang)管提出(chu)了夏(xia)比(bi)(bi)低溫沖(chong)擊試(shi)驗的(de)要求,在(zai)夏(xia)比(bi)(bi)低溫沖(chong)擊試(shi)驗的(de)試(shi)驗溫度(du)與(yu)合格(ge)值上(shang)差異(yi)較大。






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