有的設計人員咨詢浙江至(zhi)德(de)鋼業(ye)(ye)有限(xian)公司工程師(shi)工業(ye)(ye)管道與(yu)輸氣管道的壁厚(hou)計算(suan)(suan)是(shi)否(fou)可以統一或者互(hu)相替(ti)代使用?因(yin)兩者的壁厚(hou)計算(suan)(suan)具有以下區別,所以肯定是(shi)不(bu)能混(hun)用的。



一、工業管(guan)道(dao)與輸氣管(guan)道(dao)直管(guan)壁(bi)厚計算(suan)公(gong)式比較


 1. 壁(bi)厚(hou)計算理(li)論基礎(chu)比較


   承受(shou)內壓的直(zhi)管屬于(yu)旋轉(zhuan)殼體的一種(zhong),旋轉(zhuan)殼體應(ying)(ying)(ying)力(li)(li)(li)(li)分(fen)析理論(lun)有兩(liang)類:一類是忽略彎矩(ju)的無力(li)(li)(li)(li)矩(ju)理論(lun)一-薄膜理論(lun),導出(chu)的是壁(bi)厚(hou)計算(suan)的薄膜應(ying)(ying)(ying)力(li)(li)(li)(li)公(gong)(gong)式,該公(gong)(gong)式計算(suan)的是沿壁(bi)厚(hou)均(jun)勻(yun)分(fen)布(bu)(bu)的兩(liang)向(xiang)(xiang)應(ying)(ying)(ying)力(li)(li)(li)(li),即軸向(xiang)(xiang)應(ying)(ying)(ying)力(li)(li)(li)(li)和(he)周(zhou)向(xiang)(xiang)應(ying)(ying)(ying)力(li)(li)(li)(li),忽略了(le)徑向(xiang)(xiang)應(ying)(ying)(ying)力(li)(li)(li)(li)。另一類是彈性力(li)(li)(li)(li)學應(ying)(ying)(ying)力(li)(li)(li)(li)分(fen)析理論(lun)一一拉美公(gong)(gong)式,共三個方向(xiang)(xiang)的應(ying)(ying)(ying)力(li)(li)(li)(li),周(zhou)向(xiang)(xiang)應(ying)(ying)(ying)力(li)(li)(li)(li)和(he)徑向(xiang)(xiang)應(ying)(ying)(ying)力(li)(li)(li)(li)沿壁(bi)厚(hou)非線性分(fen)布(bu)(bu),軸向(xiang)(xiang)應(ying)(ying)(ying)力(li)(li)(li)(li)沿壁(bi)厚(hou)均(jun)勻(yun)分(fen)布(bu)(bu)。


   GB 50251《輸(shu)氣管(guan)(guan)道(dao)(dao)工(gong)程設計規范》采用(yong)(yong)ASME B31.8《輸(shu)氣和配氣管(guan)(guan)道(dao)(dao)系統》的(de)(de)壁厚(hou)計算公(gong)(gong)(gong)式(shi),公(gong)(gong)(gong)式(shi)源(yuan)于無力矩(ju)理論(lun)的(de)(de)薄膜理論(lun)應(ying)力公(gong)(gong)(gong)式(shi)。GB/T 20801、GB 50316、SH/T 3059等標準采用(yong)(yong)ASME B31.3《工(gong)藝(yi)管(guan)(guan)道(dao)(dao)》的(de)(de)壁厚(hou)計算公(gong)(gong)(gong)式(shi),公(gong)(gong)(gong)式(shi)是拉美(mei)公(gong)(gong)(gong)式(shi)的(de)(de)經驗近似式(shi)。輸(shu)氣管(guan)(guan)道(dao)(dao)壁厚(hou)計算公(gong)(gong)(gong)式(shi)的(de)(de)理論(lun)基(ji)礎采用(yong)(yong)無力矩(ju)理論(lun)-薄膜理論(lun),而(er)工(gong)業管(guan)(guan)道(dao)(dao)采用(yong)(yong)彈性力學應(ying)力分(fen)析理論(lun)-拉美(mei)公(gong)(gong)(gong)式(shi)。


 2. 安全(quan)系(xi)數取(qu)值方式的比較(jiao)


   輸氣(qi)管(guan)(guan)道(dao)(dao)(dao)由于(yu)需穿越城市、村鎮等,根(gen)據管(guan)(guan)道(dao)(dao)(dao)通過區(qu)域的不(bu)同條件,采用(yong)(yong)改變管(guan)(guan)道(dao)(dao)(dao)應力水平(ping)(即改變管(guan)(guan)道(dao)(dao)(dao)壁厚)以(yi)強(qiang)度(du)確保管(guan)(guan)道(dao)(dao)(dao)自(zi)身的安全(quan)(quan),為管(guan)(guan)道(dao)(dao)(dao)周圍環境提供安全(quan)(quan)保障(采用(yong)(yong)不(bu)同的強(qiang)度(du)設(she)計系數(shu)F)的理(li)念,同時也體現了管(guan)(guan)道(dao)(dao)(dao)的經濟成(cheng)本的合理(li)性(xing)。GB50251中規(gui)(gui)定的強(qiang)度(du)設(she)計系數(shu)F值(zhi),一級地(di)區(qu)為0.8,四級地(di)區(qu)為0.4。強(qiang)度(du)設(she)計系數(shu)F值(zhi)的規(gui)(gui)定與(yu)取(qu)值(zhi)源自(zi)ASME B31.8《輸氣(qi)和配(pei)氣(qi)管(guan)(guan)道(dao)(dao)(dao)系統》。


   工(gong)業(ye)(ye)管(guan)道(dao)壁厚計(ji)算中(zhong)(zhong)(zhong)(zhong),設計(ji)溫度(du)(du)下的(de)(de)(de)材(cai)(cai)料(liao)許(xu)用應(ying)(ying)力(li)由(you)材(cai)(cai)料(liao)的(de)(de)(de)力(li)學性能除(chu)以相應(ying)(ying)的(de)(de)(de)安全(quan)(quan)(quan)(quan)(quan)系數而得(de),GB/T 20801、GB 50316、SH/T 3059規定的(de)(de)(de)材(cai)(cai)料(liao)安全(quan)(quan)(quan)(quan)(quan)系數與GB 150中(zhong)(zhong)(zhong)(zhong)材(cai)(cai)料(liao)安全(quan)(quan)(quan)(quan)(quan)系數的(de)(de)(de)要求相同(tong)。由(you)于工(gong)業(ye)(ye)管(guan)道(dao)處(chu)于有限范(fan)(fan)圍的(de)(de)(de)工(gong)廠環境(jing)中(zhong)(zhong)(zhong)(zhong),材(cai)(cai)料(liao)的(de)(de)(de)安全(quan)(quan)(quan)(quan)(quan)系數根據材(cai)(cai)料(liao)的(de)(de)(de)類型(xing)和力(li)學性能(強度(du)(du)極限、屈服極限、持久強度(du)(du)、蠕變極限)的(de)(de)(de)不同(tong)而取值(zhi)(zhi),按照規范(fan)(fan)規定選取許(xu)用應(ying)(ying)力(li)值(zhi)(zhi)。許(xu)用應(ying)(ying)力(li)值(zhi)(zhi)的(de)(de)(de)大(da)小與工(gong)業(ye)(ye)管(guan)道(dao)所處(chu)的(de)(de)(de)環境(jing)條件完全(quan)(quan)(quan)(quan)(quan)無關,在GB/T20801、GB 50316、SH/T 3059等中(zhong)(zhong)(zhong)(zhong)規定使用應(ying)(ying)力(li)表中(zhong)(zhong)(zhong)(zhong)的(de)(de)(de)值(zhi)(zhi),既(ji)體現(xian)了(le)許(xu)用應(ying)(ying)力(li)所表達的(de)(de)(de)安全(quan)(quan)(quan)(quan)(quan)強度(du)(du),又(you)體現(xian)了(le)工(gong)程設計(ji)的(de)(de)(de)經(jing)濟合理性。


   輸氣管道(dao)和工業(ye)管道(dao)壁厚計(ji)算公式中安(an)全系數的區別(bie),在(zai)安(an)全理念(nian)和規范內容上存在(zai)差(cha)異,在(zai)設計(ji)上是無法統(tong)一(yi)的。


 3. 鋼管壁厚附加裕(yu)量的比較(jiao)


   輸氣管(guan)道在用公(gong)式得出計算壁厚之后,圓整到鋼(gang)管(guan)標準規定(ding)的(de)壁厚,一般沒有考慮材料厚度偏(pian)差(cha)(cha)和腐蝕(shi)裕量(liang)。但(dan)是(shi)ASME B31.8規定(ding)采用該規范所列鋼(gang)管(guan),已經考慮了(le)鋼(gang)管(guan)的(de)壁厚負(fu)偏(pian)差(cha)(cha),并且加(jia)了(le)裕量(liang),例如,如采用API5L,則不必再另加(jia)厚度負(fu)偏(pian)差(cha)(cha)了(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(xuan)用的比較


  由于輸(shu)(shu)氣(qi)管(guan)(guan)(guan)(guan)道(dao)(dao)距離長(chang),鋼管(guan)(guan)(guan)(guan)用量大,天(tian)然(ran)(ran)氣(qi)輸(shu)(shu)送(song)量大,輸(shu)(shu)氣(qi)管(guan)(guan)(guan)(guan)道(dao)(dao)朝(chao)著(zhu)高壓力、大直(zhi)徑方(fang)向(xiang)發展,鋼管(guan)(guan)(guan)(guan)材(cai)料也朝(chao)著(zhu)高強度、微(wei)合金的(de)(de)(de)(de)方(fang)向(xiang)發展。與(yu)(yu)輸(shu)(shu)氣(qi)管(guan)(guan)(guan)(guan)道(dao)(dao)工程相配套(tao)的(de)(de)(de)(de)鋼管(guan)(guan)(guan)(guan)也有了自(zi)成體系(xi)的(de)(de)(de)(de)鋼管(guan)(guan)(guan)(guan)標準(zhun),在(zai)國際上(shang)(shang)得到廣泛(fan)(fan)應用的(de)(de)(de)(de)鋼管(guan)(guan)(guan)(guan)標準(zhun)是美國標準(zhun)API5L。該(gai)標準(zhun)的(de)(de)(de)(de)最(zui)高鋼級為L830M(PSL2),規(gui)定的(de)(de)(de)(de)屈服(fu)強度最(zui)小值為830 MPa。ISO 3183《石(shi)油天(tian)然(ran)(ran)氣(qi)工業(ye)(ye)管(guan)(guan)(guan)(guan)線輸(shu)(shu)送(song)系(xi)統用鋼管(guan)(guan)(guan)(guan)》是在(zai)API5L《管(guan)(guan)(guan)(guan)線鋼管(guan)(guan)(guan)(guan)規(gui)范(fan)》基礎(chu)(chu)上(shang)(shang)編制(zhi)的(de)(de)(de)(de)。GB/T 9711《石(shi)油天(tian)然(ran)(ran)氣(qi)工業(ye)(ye) 管(guan)(guan)(guan)(guan)線輸(shu)(shu)送(song)系(xi)統用鋼管(guan)(guan)(guan)(guan)》是在(zai)ISO 3183標準(zhun)基礎(chu)(chu)上(shang)(shang)修(xiu)改(gai)編制(zhi)的(de)(de)(de)(de),該(gai)標準(zhun)得到了廣泛(fan)(fan)應用。與(yu)(yu)工業(ye)(ye)管(guan)(guan)(guan)(guan)道(dao)(dao)用鋼管(guan)(guan)(guan)(guan)在(zai)技術上(shang)(shang)有重大區別。GB 50349《氣(qi)田集輸(shu)(shu)設計規(gui)范(fan)》規(gui)定氣(qi)田集輸(shu)(shu)管(guan)(guan)(guan)(guan)道(dao)(dao)用鋼管(guan)(guan)(guan)(guan)也是選用GB/T 9711。


  工業(ye)(ye)(ye)管(guan)(guan)(guan)(guan)道(dao)(dao)所屬裝置(zhi)的管(guan)(guan)(guan)(guan)道(dao)(dao)流(liu)體多樣化(hua)、設計參數各(ge)不相同,工業(ye)(ye)(ye)管(guan)(guan)(guan)(guan)道(dao)(dao)的器材(cai)選(xuan)(xuan)用(yong)(yong)尚(shang)無自成體系的統一標(biao)(biao)準(zhun),均(jun)是使用(yong)(yong)相應(ying)的鋼(gang)(gang)(gang)(gang)材(cai)和鋼(gang)(gang)(gang)(gang)管(guan)(guan)(guan)(guan)標(biao)(biao)準(zhun),例如(ru)國(guo)標(biao)(biao)鋼(gang)(gang)(gang)(gang)管(guan)(guan)(guan)(guan)常用(yong)(yong)標(biao)(biao)準(zhun):GB/T13793《直(zhi)縫(feng)(feng)電焊鋼(gang)(gang)(gang)(gang)管(guan)(guan)(guan)(guan)》,GB/T9948《石油裂化(hua)用(yong)(yong)無縫(feng)(feng)鋼(gang)(gang)(gang)(gang)管(guan)(guan)(guan)(guan)》,GB/T 6479《高壓化(hua)肥設備用(yong)(yong)無縫(feng)(feng)鋼(gang)(gang)(gang)(gang)管(guan)(guan)(guan)(guan)》,GB/T8163《輸送流(liu)體用(yong)(yong)無縫(feng)(feng)鋼(gang)(gang)(gang)(gang)管(guan)(guan)(guan)(guan)》,GB/T3087《低(di)中壓鍋(guo)爐用(yong)(yong)無縫(feng)(feng)鋼(gang)(gang)(gang)(gang)管(guan)(guan)(guan)(guan)》,GB/T5310《高壓鍋(guo)爐用(yong)(yong)無縫(feng)(feng)鋼(gang)(gang)(gang)(gang)管(guan)(guan)(guan)(guan)》等(deng)數十個,工業(ye)(ye)(ye)管(guan)(guan)(guan)(guan)道(dao)(dao)器材(cai)選(xuan)(xuan)用(yong)(yong)具體規定(ding)與輸氣(qi)(qi)管(guan)(guan)(guan)(guan)道(dao)(dao)的材(cai)料(liao)要求是大(da)不一樣的,輸氣(qi)(qi)管(guan)(guan)(guan)(guan)道(dao)(dao)與工業(ye)(ye)(ye)管(guan)(guan)(guan)(guan)道(dao)(dao)在材(cai)料(liao)選(xuan)(xuan)用(yong)(yong)及材(cai)料(liao)標(biao)(biao)準(zhun)上(shang)均(jun)有很大(da)區(qu)別。



三(san)、管(guan)道沖擊試驗的比較


  輸氣管(guan)(guan)(guan)(guan)道(包括輸氣站(zhan))一(yi)般(ban)都在野外(wai),受自然環境(低溫(wen))的(de)(de)影響比(bi)(bi)較大,輸氣管(guan)(guan)(guan)(guan)道用鋼(gang)(gang)管(guan)(guan)(guan)(guan)對(dui)低溫(wen)沖擊(ji)(ji)韌(ren)性的(de)(de)要(yao)求較高,以(yi)防止鋼(gang)(gang)管(guan)(guan)(guan)(guan)脆(cui)性斷(duan)裂擴(kuo)展和(he)控(kong)制延性斷(duan)裂擴(kuo)展。我國對(dui)干線和(he)站(zhan)場用鋼(gang)(gang)管(guan)(guan)(guan)(guan)提出了在API5L的(de)(de)基(ji)礎上對(dui)鋼(gang)(gang)管(guan)(guan)(guan)(guan)和(he)焊(han)縫進行夏比(bi)(bi)沖擊(ji)(ji)試驗(yan)的(de)(de)要(yao)求,規定(ding)其試驗(yan)溫(wen)度應低于(yu)管(guan)(guan)(guan)(guan)道通過當地的(de)(de)最低環境溫(wen)度,一(yi)般(ban)取-10℃,-20℃、-30℃,夏比(bi)(bi)沖擊(ji)(ji)韌(ren)性合格值(zhi)根據不同鋼(gang)(gang)級和(he)管(guan)(guan)(guan)(guan)徑分別為27J、40J、54J、80J(3個試樣最小平均值(zhi))。


  工(gong)業管道對管道設(she)計溫(wen)度(du)≤-20℃而高于鋼(gang)材使用溫(wen)度(du)下限的(de)碳素鋼(gang)、低(di)合金(jin)(jin)鋼(gang)、中合金(jin)(jin)鋼(gang)和(he)高合金(jin)(jin)鐵素體鋼(gang),要求進(jin)行夏比低(di)溫(wen)沖擊(ji)試驗,試驗沖擊(ji)功合格值(zhi)根據不同(tong)的(de)鋼(gang)材分別為18J、20J、27J、31J(3個試樣(yang)平均值(zhi)),GB/T 20801、GB/T 50316、SH/T 3059等標(biao)注中均有明確(que)規定。


  輸(shu)氣管(guan)道(dao)與工(gong)業管(guan)道(dao)設計規(gui)范對鋼管(guan)提(ti)出了夏比(bi)低溫(wen)(wen)沖擊試(shi)驗的(de)要求,在夏比(bi)低溫(wen)(wen)沖擊試(shi)驗的(de)試(shi)驗溫(wen)(wen)度(du)與合格值上差異較大。






聯系方式.jpg