管道工程(cheng)中常用的有色(se)金屬(Non-ferrous Metal)有銅、鋁、鉛和(he)鋅等。
1. 銅(Copper)
銅(tong)又分(fen)純銅(tong)(俗稱紫銅(tong))、黃銅(tong)和(he)青銅(tong)等(deng)(deng)。有(you)關銅(tong)管(guan)的(de)標準(zhun)規范(fan)包括 ASTM B42、ASTM B43、ASTM B315、ASTM B466、ASTM B467,有(you)關銅(tong)管(guan)件的(de)標準(zhun)規范(fan)有(you)ASMEB16.24、ASME B16.22、ASME B16.15、ASME B16.18等(deng)(deng)。
a. 純(chun)銅(Copper)
純(chun)銅(tong)呈紫紅色,有良好的(de)(de)導電性(xing)、導熱性(xing)和(he)(he)耐(nai)大(da)氣腐蝕性(xing),熔點(dian)為(wei)1083℃。在(zai)管(guan)道(dao)(dao)(dao)工程(cheng)中常(chang)用(yong)純(chun)銅(tong)制成鋼管(guan)和(he)(he)法蘭(lan)墊片(pian)。因純(chun)銅(tong)硬度(du)較低(di),退火后變得(de)更(geng)柔軟,故常(chang)用(yong)來(lai)制作(zuo)高(gao)壓管(guan)道(dao)(dao)(dao)中 的(de)(de)法蘭(lan)墊片(pian)。純(chun)銅(tong)管(guan)的(de)(de)低(di)溫(wen)(wen)(wen)性(xing)能比鋼材好,故純(chun)銅(tong)管(guan)常(chang)用(yong)于(yu)空分設備管(guan)道(dao)(dao)(dao)、冷(leng)凍管(guan)道(dao)(dao)(dao)和(he)(he)儀表管(guan)道(dao)(dao)(dao)。純(chun)銅(tong)的(de)(de)高(gao)溫(wen)(wen)(wen)性(xing)能差,在(zai)120℃以(yi)下(xia),允(yun)(yun)許(xu)抗拉強(qiang)(qiang)度(du)為(wei)29.43MPa。溫(wen)(wen)(wen)度(du)若(ruo)再升(sheng)高(gao),其(qi)機械強(qiang)(qiang)度(du)則急(ji)劇下(xia)降(jiang),當溫(wen)(wen)(wen)度(du)上升(sheng)至250℃時,其(qi)允(yun)(yun)許(xu)抗拉強(qiang)(qiang)度(du)只相(xiang)當于(yu)常(chang)溫(wen)(wen)(wen)時的(de)(de)2/3,已不宜(yi)在(zai)壓力下(xia)使用(yong)。
常用的(de)純銅牌號為T2、T3、T4,雜質含(han)量T2最少,T4最多。
b. 黃銅(Brass)
黃(huang)銅(tong)是(shi)銅(tong)和(he)鋅(xin)的(de)合金(jin),其(qi)機械強度(du)(du)(du)高,有(you)較好(hao)的(de)耐腐蝕性和(he)澆(jiao)鑄性,可(ke)用(yong)來制作管子、管件和(he)閥(fa)(fa)門等。化工上常用(yong)的(de)有(you)H80、H68、H62(“H”是(shi)黃(huang)銅(tong)代號,后邊的(de)數字表示(shi)合金(jin)中銅(tong)的(de)平均含量)。H80比(bi)H68塑性好(hao)。進(jin)行強度(du)(du)(du)計算時(shi),在(zai)120℃以(yi)下,黃(huang)銅(tong)允(yun)許抗拉強度(du)(du)(du)為(wei)29.43MPa。隨著(zhu)溫(wen)度(du)(du)(du)升高,其(qi)強度(du)(du)(du)則急劇下降,當溫(wen)度(du)(du)(du)未超過(guo)(guo)225℃時(shi),黃(huang)銅(tong)閥(fa)(fa)件可(ke)用(yong)在(zai)壓力不超過(guo)(guo)1.6MPa的(de)管道(dao)中。
c. 青銅(Bronze)
青(qing)銅(tong)是銅(tong)和(he)錫(xi)的合金,又稱錫(xi)青(qing)銅(tong)。由(you)于(yu)錫(xi)的價格較高,故制造青(qing)銅(tong)也常用其他元素(su)代替,因而(er)(er)又有無(wu)錫(xi)青(qing)銅(tong),如鋁青(qing)銅(tong)、鉛(qian)青(qing)銅(tong)、硅青(qing)銅(tong)等(deng)。青(qing)銅(tong)通常由(you)澆(jiao)鑄而(er)(er)成(cheng),其強(qiang)度(du)、硬度(du)及(ji)耐腐蝕性都比(bi)黃銅(tong)好。青(qing)銅(tong)常用于(yu)制造蝸(gua)輪(lun)、齒(chi)輪(lun)、輪(lun),以及(ji)管(guan)道工程(cheng)中的閥件和(he)管(guan)件等(deng)。
2. 鋁(lv)(Aluminum)
鋁(lv)的熔點為527℃,它具有(you)良好(hao)的導熱性和(he)導電性,強(qiang)度和(he)硬度較(jiao)低(di),可(ke)塑性好(hao)。鋁(lv)容易氧化(hua)(hua),在(zai)空(kong)氣中(zhong),鋁(lv)的表面能形(xing)成一層極薄(bo)的氧化(hua)(hua)鋁(lv)保(bao)護膜(mo),防(fang)止繼續(xu)氧化(hua)(hua)。鋁(lv)合金(jin)薄(bo)板常作為壓(ya)力管道絕熱工程的管子、塔、罐、換熱器、閥門、法蘭(lan)以(yi)及其他平壁設備保(bao)護層材料。
純鋁(lv)(lv)的強度和(he)硬度雖然很低,但若加入其他(ta)元(yuan)素可以提高。鋁(lv)(lv)合金(jin)分(fen)為鑄造鋁(lv)(lv)合金(jin)和(he)可壓迫變形的鋁(lv)(lv)合金(jin)兩大類(lei)。管道工程(cheng)中,常用(yong)L2和(he)L3牌號(hao)的鋁(lv)(lv)管輸送硝酸和(he)醋酸等,但是鋁(lv)(lv)不能抵(di)抗堿(jian)性腐蝕。當溫度高于150℃時,鋁(lv)(lv)管不宜用(yong)于壓力管道。鋁(lv)(lv)和(he)鋁(lv)(lv)合金(jin)管的標準規范有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-鋁合金管法蘭(lan)”。
3. 鉛(Lead)
鉛(qian)(qian)(qian)(qian)是一種暗灰(hui)色的金(jin)(jin)屬,熔點為(wei)327℃,它有很好的耐腐(fu)蝕性能,常(chang)用(yong)(yong)(yong)來制作硫(liu)酸(suan)設(she)備和管道(dao)襯(chen)里。鉛(qian)(qian)(qian)(qian)質(zhi)軟,可塑性好,管道(dao)工(gong)程中(zhong)(zhong)常(chang)用(yong)(yong)(yong)鉛(qian)(qian)(qian)(qian)管。在(zai)安裝鑄鐵(tie)管承插口時(shi),常(chang)用(yong)(yong)(yong)鉛(qian)(qian)(qian)(qian)作為(wei)接口填塞材(cai)料,以牌號為(wei)Pb-6的鉛(qian)(qian)(qian)(qian)較(jiao)適宜。硬(ying)鉛(qian)(qian)(qian)(qian)是鉛(qian)(qian)(qian)(qian)和銻(ti)的合金(jin)(jin),它的抗腐(fu)蝕性略低于純鉛(qian)(qian)(qian)(qian),但機械強(qiang)度(du)較(jiao)高,常(chang)用(yong)(yong)(yong)于制造耐酸(suan)設(she)備。鉛(qian)(qian)(qian)(qian)蒸氣有毒(du),故(gu)熔化鉛(qian)(qian)(qian)(qian)時(shi),要(yao)防(fang)止(zhi)燙(tang)傷和鉛(qian)(qian)(qian)(qian)中(zhong)(zhong)毒(du)。在(zai)化工(gong)行業中(zhong)(zhong),鉛(qian)(qian)(qian)(qian)主(zhu)要(yao)用(yong)(yong)(yong)在(zai)處理硫(liu)酸(suan)的設(she)備上。Pb-4用(yong)(yong)(yong)于設(she)備內襯(chen),Pb-6用(yong)(yong)(yong)于管道(dao)接頭,硬(ying)鉛(qian)(qian)(qian)(qian)可制造硫(liu)酸(suan)工(gong)業用(yong)(yong)(yong)的泵、閥門(men)、管道(dao)等。
4. 鋅(Zinc)
鋅呈淺(qian)灰(hui)色,熔點為419℃,它有較好的耐腐蝕性(xing)和(he)力學(xue)性(xing)能。有些鋼管(guan)和(he)管(guan)件為增強(qiang)耐腐蝕性(xing)能,常在表面鍍一層(ceng)鋅,如室內(nei)給水工程中(zhong)常用的鍍鋅管(guan)。