管道工程中常用(yong)的有(you)色(se)金屬(Non-ferrous Metal)有(you)銅、鋁、鉛和鋅(xin)等。


1. 銅(Copper)


  銅又(you)分(fen)純(chun)銅(俗(su)稱(cheng)紫銅)、黃銅和青銅等。有關銅管的(de)標準規范(fan)包括 ASTM B42、ASTM B43、ASTM B315、ASTM B466、ASTM B467,有關銅管件的(de)標準規范(fan)有ASMEB16.24、ASME B16.22、ASME B16.15、ASME B16.18等。


 a. 純銅(tong)(Copper)


    純(chun)銅(tong)(tong)呈紫紅色,有良好的導電性、導熱性和耐(nai)大氣(qi)腐蝕性,熔點為(wei)1083℃。在(zai)管(guan)道(dao)工程中常用(yong)純(chun)銅(tong)(tong)制成鋼管(guan)和法蘭墊(dian)(dian)片。因純(chun)銅(tong)(tong)硬度較(jiao)低(di),退(tui)火后變(bian)得更柔軟(ruan),故(gu)常用(yong)來制作高壓管(guan)道(dao)中   的法蘭墊(dian)(dian)片。純(chun)銅(tong)(tong)管(guan)的低(di)溫性能比鋼材好,故(gu)純(chun)銅(tong)(tong)管(guan)常用(yong)于空分設備管(guan)道(dao)、冷凍管(guan)道(dao)和儀表(biao)管(guan)道(dao)。純(chun)銅(tong)(tong)的高溫性能差(cha),在(zai)120℃以(yi)下(xia),允許抗拉(la)強(qiang)(qiang)度為(wei)29.43MPa。溫度若(ruo)再升高,其機械強(qiang)(qiang)度則急劇下(xia)降,當溫度上升至250℃時(shi)(shi),其允許抗拉(la)強(qiang)(qiang)度只相當于常溫時(shi)(shi)的2/3,已不宜在(zai)壓力下(xia)使用(yong)。


    常用的純銅(tong)牌號為T2、T3、T4,雜質含量(liang)T2最(zui)少,T4最(zui)多。


  b. 黃(huang)銅(tong)(Brass)


   黃銅(tong)是銅(tong)和(he)鋅(xin)的(de)合金,其機械強度(du)(du)高(gao)(gao),有較好的(de)耐(nai)腐蝕性和(he)澆鑄(zhu)性,可(ke)用(yong)(yong)來制作管子、管件和(he)閥(fa)門(men)等。化工(gong)上常用(yong)(yong)的(de)有H80、H68、H62(“H”是黃銅(tong)代(dai)號,后邊(bian)的(de)數字(zi)表示(shi)合金中銅(tong)的(de)平(ping)均含(han)量)。H80比H68塑性好。進行強度(du)(du)計算時,在120℃以(yi)下(xia),黃銅(tong)允許抗拉強度(du)(du)為29.43MPa。隨著溫度(du)(du)升高(gao)(gao),其強度(du)(du)則急劇下(xia)降(jiang),當溫度(du)(du)未超過(guo)225℃時,黃銅(tong)閥(fa)件可(ke)用(yong)(yong)在壓力不(bu)超過(guo)1.6MPa的(de)管道(dao)中。


  c. 青(qing)銅(Bronze)


    青(qing)(qing)(qing)(qing)銅(tong)(tong)(tong)(tong)是銅(tong)(tong)(tong)(tong)和錫(xi)的(de)合金,又稱錫(xi)青(qing)(qing)(qing)(qing)銅(tong)(tong)(tong)(tong)。由于(yu)錫(xi)的(de)價格較(jiao)高,故制造青(qing)(qing)(qing)(qing)銅(tong)(tong)(tong)(tong)也(ye)常用(yong)其他(ta)元素代替,因(yin)而(er)又有無錫(xi)青(qing)(qing)(qing)(qing)銅(tong)(tong)(tong)(tong),如鋁青(qing)(qing)(qing)(qing)銅(tong)(tong)(tong)(tong)、鉛青(qing)(qing)(qing)(qing)銅(tong)(tong)(tong)(tong)、硅(gui)青(qing)(qing)(qing)(qing)銅(tong)(tong)(tong)(tong)等。青(qing)(qing)(qing)(qing)銅(tong)(tong)(tong)(tong)通常由澆鑄而(er)成,其強度、硬度及耐腐(fu)蝕性都比黃銅(tong)(tong)(tong)(tong)好(hao)。青(qing)(qing)(qing)(qing)銅(tong)(tong)(tong)(tong)常用(yong)于(yu)制造蝸(gua)輪(lun)(lun)、齒(chi)輪(lun)(lun)、輪(lun)(lun),以及管道工程中的(de)閥(fa)件(jian)和管件(jian)等。



2. 鋁(Aluminum)


  鋁(lv)(lv)的熔點為(wei)527℃,它具有良好的導熱性和導電(dian)性,強(qiang)度(du)和硬度(du)較低,可塑性好。鋁(lv)(lv)容易(yi)氧化,在空氣中,鋁(lv)(lv)的表面(mian)能(neng)形成(cheng)一層(ceng)極薄的氧化鋁(lv)(lv)保護膜,防止繼續氧化。鋁(lv)(lv)合(he)金(jin)薄板常作為(wei)壓力管(guan)道絕熱工程(cheng)的管(guan)子、塔(ta)、罐、換熱器、閥門、法蘭以及其他(ta)平壁設(she)備保護層(ceng)材料。


  純鋁(lv)的(de)強(qiang)度(du)(du)和(he)(he)硬(ying)度(du)(du)雖然很低(di),但(dan)若(ruo)加入其他元素(su)可以提(ti)高。鋁(lv)合金分為鑄造鋁(lv)合金和(he)(he)可壓(ya)迫變形的(de)鋁(lv)合金兩大(da)類。管(guan)(guan)道工程(cheng)中,常用(yong)L2和(he)(he)L3牌(pai)號的(de)鋁(lv)管(guan)(guan)輸(shu)送硝(xiao)酸和(he)(he)醋酸等,但(dan)是鋁(lv)不(bu)能抵(di)抗堿性腐蝕(shi)。當溫度(du)(du)高于150℃時,鋁(lv)管(guan)(guan)不(bu)宜用(yong)于壓(ya)力管(guan)(guan)道。鋁(lv)和(he)(he)鋁(lv)合金管(guan)(guan)的(de)標準規范有ASTM B241、ASTM B26、ASTM B108、ASTM B209、ASTM B210、ASTM B211、ASTM


  B221、ASTMI B234、ASTM B247 以及 ASME B31.3的“附錄L-鋁合金管(guan)法蘭”。


3. 鉛(Lead)


  鉛(qian)(qian)(qian)(qian)(qian)是一種暗(an)灰(hui)色的(de)金(jin)(jin)屬,熔點為327℃,它有(you)很好的(de)耐(nai)腐(fu)(fu)蝕(shi)性能,常(chang)用(yong)來制(zhi)作硫酸設(she)備(bei)和(he)管(guan)道襯里。鉛(qian)(qian)(qian)(qian)(qian)質軟,可塑性好,管(guan)道工(gong)(gong)程中(zhong)(zhong)常(chang)用(yong)鉛(qian)(qian)(qian)(qian)(qian)管(guan)。在(zai)安裝(zhuang)鑄鐵(tie)管(guan)承插口(kou)時,常(chang)用(yong)鉛(qian)(qian)(qian)(qian)(qian)作為接(jie)口(kou)填(tian)塞材料,以牌號(hao)為Pb-6的(de)鉛(qian)(qian)(qian)(qian)(qian)較適宜。硬鉛(qian)(qian)(qian)(qian)(qian)是鉛(qian)(qian)(qian)(qian)(qian)和(he)銻的(de)合金(jin)(jin),它的(de)抗腐(fu)(fu)蝕(shi)性略低于純鉛(qian)(qian)(qian)(qian)(qian),但機(ji)械強度較高(gao),常(chang)用(yong)于制(zhi)造耐(nai)酸設(she)備(bei)。鉛(qian)(qian)(qian)(qian)(qian)蒸(zheng)氣有(you)毒(du),故熔化鉛(qian)(qian)(qian)(qian)(qian)時,要防止燙傷和(he)鉛(qian)(qian)(qian)(qian)(qian)中(zhong)(zhong)毒(du)。在(zai)化工(gong)(gong)行業中(zhong)(zhong),鉛(qian)(qian)(qian)(qian)(qian)主要用(yong)在(zai)處(chu)理硫酸的(de)設(she)備(bei)上(shang)。Pb-4用(yong)于設(she)備(bei)內襯,Pb-6用(yong)于管(guan)道接(jie)頭(tou),硬鉛(qian)(qian)(qian)(qian)(qian)可制(zhi)造硫酸工(gong)(gong)業用(yong)的(de)泵(beng)、閥門(men)、管(guan)道等(deng)。


4. 鋅(Zinc)


  鋅呈淺(qian)灰色,熔(rong)點為(wei)419℃,它有較好的耐腐(fu)蝕性和力學性能(neng)。有些鋼管(guan)和管(guan)件為(wei)增強耐腐(fu)蝕性能(neng),常在表面鍍(du)一層鋅,如(ru)室(shi)內給(gei)水工程中常用的鍍(du)鋅管(guan)。