直縫鋼管是通常分為公製電焊鋼管、電焊薄壁管、變(bian)壓(ya)器(qi)冷(leng)卻(que)油(you)管(guan)等(deng)等(deng)。直(zhi)縫(feng)焊(han)管(guan)生(sheng)產(chan)工(gong)藝(yi)簡(jian)單(dan),成(cheng)本(ben)低(di)。直(zhi)縫(feng)鋼(gang)管(guan)按(an)生(sheng)產(chan)工(gong)藝(yi)可(ke)分(fen)為(wei)高(gao)頻(pin)直(zhi)縫(feng)鋼(gang)管(guan)和(he)埋(mai)弧(hu)焊(han)直(zhi)縫(feng)鋼(gang)管(guan),高(gao)頻(pin)焊(han)管(guan)機(ji)組(zu)通(tong)常(chang)由(you)滾(gun)壓(ya)成(cheng)型(xing)、高頻焊接、擠壓、冷卻、定徑、飛鋸切斷等部件組成,機組的前端配有儲料活套,機組的後端配有鋼管翻轉機架;電氣部分主要有高頻發生器、直流勵磁發電機和儀表自動控製裝置等組成。
直縫鋼管一般焊管:輸送低壓流體。用Q195、Q215A、Q235A鋼、Q235B普碳製造 。鋼管要進行水壓、彎曲、壓(ya)扁(bian)等(deng)實(shi)驗(yan),對(dui)表(biao)麵(mian)質(zhi)量(liang)有(you)一(yi)定(ding)要(yao)求(qiu),。焊(han)管(guan)的(de)規(gui)格(ge)用(yong)公(gong)稱(cheng)口(kou)徑(jing)表(biao)示(shi)公(gong)稱(cheng)口(kou)徑(jing)與(yu)實(shi)際(ji)不(bu)同(tong),焊(han)管(guan)按(an)規(gui)定(ding)壁(bi)厚(hou)有(you)普(pu)通(tong)鋼(gang)管(guan)和(he)加(jia)厚(hou)鋼(gang)管(guan)兩(liang)種(zhong),鋼(gang)管(guan)按(an)管(guan)端(duan)形(xing)式(shi)又(you)分(fen)帶(dai)螺(luo)紋(wen)和(he)不(bu)帶(dai)螺(luo)紋(wen)兩(liang)種(zhong)
3PE防腐鋼管在製作時常用無縫鋼管,螺旋鋼管和直縫鋼管作為基材。三層結構的聚乙烯防腐塗層以其良好的抗腐蝕性、抗(kang)水(shui)氣(qi)滲(shen)透(tou)性(xing)性(xing)能(neng),在(zai)埋(mai)地(di)管(guan)道(dao)行(xing)業(ye)得(de)到(dao)了(le)廣(guang)泛(fan)應(ying)用(yong)。防(fang)腐(fu)層(ceng)對(dui)於(yu)埋(mai)地(di)管(guan)道(dao)的(de)壽(shou)命(ming)來(lai)說(shuo)是(shi)至(zhi)關(guan)重(zhong)要(yao)的(de),之(zhi)所(suo)以(yi)有(you)的(de)管(guan)道(dao)埋(mai)在(zai)地(di)下(xia)幾(ji)十(shi)年(nian)不(bu)腐(fu)蝕(shi),有(you)的(de)幾(ji)年(nian)因(yin)腐(fu)蝕(shi)發(fa)生(sheng)泄(xie)露(lu)。就(jiu)是(shi)因(yin)為(wei)它(ta)們(men)采(cai)用(yong)了(le)不(bu)同(tong)的(de)外(wai)防(fang)腐(fu)層(ceng)。
3PE防腐鋼管是將2PE防fang腐fu層ceng和he環huan氧yang粉fen末mo防fang腐fu鋼gang管guan塗tu層ceng結jie合he起qi來lai而er產chan生sheng的de一yi種zhong新xin的de防fang腐fu形xing式shi。塗tu層ceng是shi底di層ceng與yu鋼gang管guan麵mian所suo接jie觸chu的de是shi環huan氧yang粉fen末mo防fang腐fu塗tu層ceng中zhong間jian層ceng為wei粘zhan合he劑ji,麵層為高密度聚乙烯防腐塗層。3pe防腐塗層綜合了環氧樹脂和聚乙烯材料的高抗滲性、機械性能高等特點。
3pe防腐鋼管在生產過程中為了不影響管口焊接在預留10公gong分fen左zuo右you的de預yu留liu段duan,然ran而er因yin鋼gang管guan堆dui放fang時shi間jian較jiao長chang,管guan端duan金jin屬shu腐fu蝕shi導dao致zhi的de管guan端duan出chu現xian翹qiao邊bian。如ru布bu急ji於yu使shi用yong在zai露lu天tian堆dui積ji時shi應ying在zai管guan端duan進jin行xing遮zhe蓋gai,防fang止zhi雨yu水shui造zao成cheng管guan端duan腐fu蝕shi。可ke在zai管guan端duan金jin屬shu暴bao露lu處chu塗tu刷shua可ke焊han防fang鏽xiu漆qi,以yi防fang止zhi防fang腐fu管guan在zai貯zhu存cun時shi期qi因yin腐fu蝕shi導dao致zhi防fang腐fu層ceng翹qiao邊bian。在zai生sheng產chan過guo程cheng中zhong嚴yan格ge控kong製zhi管guan端duan預yu留liu處chu焊han縫feng餘yu高gao的de修xiu磨mo質zhi量liang。在zai焊han縫feng處chu聚ju乙yi烯xi坡po口kou外wai與yu管guan體ti別bie的de部bu位wei相xiang同tong,使shi環huan氧yang粉fen末mo保bao存cun長chang度du>20mm,以防止焊縫處環氧粉末底部先被腐蝕而導致3PE防腐層翹邊。管端焊縫修磨應從焊縫修磨開端處到聚乙烯倒角處應有10-20mmmeiyouhanfengyugaodeyuguantixiangtongdejuyixicengpingzhengduan,yiquebaoguanduanjuyixipokouchurouniezhanjiezhiliang。hanfengxiumohoudeyugaoyingjinliangzuodaoyuguantipingqi,buyaoyouxianzhedeyugao,yifangzhizaidamojuyixicengdaojiaoshi,jianghuanyangfenmoyitongdamodiao。weixiumodedingduanyuxiumochudeguoduduandaojiao,yeyingyujuyixicengdaojiaoxiangtong(≤30°)防fang止zhi因yin坡po口kou處chu防fang腐fu層ceng粘zhan結jie欠qian好hao呈cheng現xian聚ju乙yi烯xi層ceng翹qiao邊bian。預yu留liu段duan環huan氧yang粉fen末mo塗tu層ceng隻zhi要yao維wei護hu完wan整zheng。管guan端duan聚ju乙yi烯xi坡po口kou加jia工gong一yi般ban廠chang家jia都dou選xuan用yong鋼gang絲si輪lun打da磨mo方fang式shi,這zhe樣yang會hui損sun壞huai環huan氧yang粉fen末mo塗tu層ceng。應ying改gai用yong機ji械xie加jia工gong坡po口kou,刀dao口kou底di層ceng要yao有you限xian位wei設she備bei來lai控kong製zhi刀dao具ju的de進jin刀dao深shen度du,防fang止zhi傷shang及ji環huan氧yang粉fen末mo塗tu層ceng受shou到dao磨mo損sun。
3PE防腐鋼管以其優越的防腐性能在石油天然氣係統得到廣泛的應用。陝氣進津高壓管道、外環線30公裏高壓天然氣管道、陝京線地下儲氣庫122公裏管線均選用的三層PE。 在3pe防腐鋼管構造中,熔結環氧粉末塗層構成的塗膜,直接粘結鋼管表麵,耐化學腐蝕性和抗陰極剝離功能良好;yuzhongjiancengjiaozhanjichenghuaxuezhanjie,quebaofangfucengjuyoulianghaodezhanjiexing。wujiaozhanjiyurongjiehuanyangfenmotucengshengchenghuaxuejian,shizhongjiancengyudicenggouchenglianghaodezhanjie;與麵層聚乙烯具有極好的親合作用。聚乙烯麵層的作用是起機械維護作用,與二層構造聚乙烯防腐層具有一樣的作用。3PE防腐鋼管具體結構為: 第1層環氧粉末(FBE>100um),第二層膠粘劑(AD)170~250um,第三層聚乙烯(PE)2.5~3.7mm。

