金屬管在管路中應用極為廣泛,現將常用金屬管介紹如下。
1. 鋼管
鋼(gang)(gang)管分(fen)為有縫(feng)鋼(gang)(gang)管和無縫(feng)鋼(gang)(gang)管兩大類(lei)。
①. 有(you)縫鋼管又(you)稱為焊(han)接鋼管
可分為(wei)(wei)低壓(ya)流(liu)體輸送(song)鋼管(guan)和(he)電焊鋼管(guan)兩類。低壓(ya)流(liu)體輸送(song)鋼管(guan)是(shi)由扁鋼管(guan)坯卷成管(guan)形并沿(yan)縫(feng)焊接而成的(de),因(yin)為(wei)(wei)它常用來輸送(song)水和(he)煤氣,故俗稱為(wei)(wei)水煤氣管(guan)。水煤氣管(guan)可分為(wei)(wei)鍍(du)鋅的(de)和(he)不鍍(du)鋅的(de);普通的(de)和(he)加(jia)厚的(de);帶(dai)螺紋的(de)和(he)不帶(dai)螺紋的(de)等(deng)類型。
水(shui)煤氣鋼管(guan)(guan)(guan)廣泛應(ying)用在小(xiao)直徑的低壓(ya)(ya)(ya)(ya)管(guan)(guan)(guan)路上,如給水(shui)、煤氣、暖氣、壓(ya)(ya)(ya)(ya)縮空(kong)氣、蒸汽、凝結水(shui)、廢(fei)氣、真(zhen)空(kong)及某些物料管(guan)(guan)(guan)路。普通鋼管(guan)(guan)(guan)正常工(gong)作壓(ya)(ya)(ya)(ya)力不大(da)于(yu)(yu)0.6MPa(表壓(ya)(ya)(ya)(ya));加(jia)厚(hou)鋼管(guan)(guan)(guan)正常工(gong)作壓(ya)(ya)(ya)(ya)力不大(da)于(yu)(yu)1MPa(表壓(ya)(ya)(ya)(ya))。正常工(gong)作溫度不宜(yi)超(chao)過(guo)175℃。最大(da)水(shui)壓(ya)(ya)(ya)(ya)試驗壓(ya)(ya)(ya)(ya)力:普通鋼管(guan)(guan)(guan)為2MPa,加(jia)厚(hou)鋼管(guan)(guan)(guan)為3MPa。
電焊(han)(han)(han)鋼(gang)管是由軟鋼(gang)板條卷成(cheng)(cheng)管形(xing)后焊(han)(han)(han)接而成(cheng)(cheng)的鋼(gang)管,分直焊(han)(han)(han)縫和螺(luo)旋焊(han)(han)(han)縫兩種(zhong)類型。
直(zhi)焊(han)縫的(de)(de)電(dian)(dian)(dian)焊(han)鋼(gang)管(guan),又可(ke)分為小直(zhi)徑電(dian)(dian)(dian)焊(han)鋼(gang)管(guan)和大直(zhi)徑電(dian)(dian)(dian)焊(han)鋼(gang)管(guan)兩類。小直(zhi)徑的(de)(de)電(dian)(dian)(dian)焊(han)鋼(gang)管(guan)外(wai)徑為5~152mm,壁厚為0.5~5.5mm.大直(zhi)徑的(de)(de)電(dian)(dian)(dian)焊(han)鋼(gang)管(guan)又稱鋼(gang)板卷管(guan),其外(wai)徑為530~2020mm,壁厚為4~16mm.螺旋縫電(dian)(dian)(dian)焊(han)鋼(gang)管(guan)外(wai)徑為219~720mm,壁厚為6~7mm.電(dian)(dian)(dian)焊(han)鋼(gang)管(guan)可(ke)用于壓力不高或無(wu)嚴格要求的(de)(de)管(guan)路上。電(dian)(dian)(dian)焊(han)鋼(gang)管(guan)的(de)(de)正(zheng)常(chang)工作溫度不宜(yi)超(chao)過200℃。
②. 無縫鋼管
是(shi)由(you)圓鋼坯加(jia)熱(re)后(hou),經穿(chuan)管機穿(chuan)孔軋制(熱(re)軋)而成(cheng)(cheng)的或者(zhe)再經過冷拔而成(cheng)(cheng)為(wei)外徑較小的管子,因(yin)為(wei)它沒有接縫,所以稱(cheng)為(wei)無縫鋼管。
無(wu)(wu)縫(feng)(feng)(feng)鋼管(guan)(guan)按照制造方法的不同,又分(fen)為(wei)熱軋無(wu)(wu)縫(feng)(feng)(feng)鋼管(guan)(guan)和冷拔無(wu)(wu)縫(feng)(feng)(feng)鋼管(guan)(guan)兩類。熱軋無(wu)(wu)縫(feng)(feng)(feng)鋼管(guan)(guan)的規(gui)格(ge):外徑為(wei)32~630mm,壁(bi)厚為(wei)2.5~75mm,管(guan)(guan)長為(wei)4~12.5m;冷拔無(wu)(wu)縫(feng)(feng)(feng)鋼管(guan)(guan)的規(gui)格(ge):外徑為(wei)2~150mm,壁(bi)厚為(wei)0.25~14mm,管(guan)(guan)長為(wei)1.5~9m。
無縫(feng)鋼(gang)管(guan)(guan)(guan)強度高(gao),可用(yong)在(zai)重(zhong)要(yao)管(guan)(guan)(guan)路(lu)(lu)(lu)上,如高(gao)壓(ya)蒸(zheng)汽和過熱蒸(zheng)汽的(de)(de)(de)管(guan)(guan)(guan)路(lu)(lu)(lu)、高(gao)壓(ya)水和過熱水管(guan)(guan)(guan)路(lu)(lu)(lu)、高(gao)壓(ya)氣體(ti)和液體(ti)管(guan)(guan)(guan)路(lu)(lu)(lu)以及輸送(song)燃燒性(xing)、爆(bao)炸(zha)性(xing)和有毒(du)害性(xing)的(de)(de)(de)物(wu)料(liao)管(guan)(guan)(guan)路(lu)(lu)(lu)等。各種(zhong)熱交換器的(de)(de)(de)管(guan)(guan)(guan)子大都采用(yong)無縫(feng)鋼(gang)管(guan)(guan)(guan)。中(zhong)、低(di)壓(ya)管(guan)(guan)(guan)路(lu)(lu)(lu)無縫(feng)鋼(gang)管(guan)(guan)(guan)的(de)(de)(de)最高(gao)工作(zuo)溫度:碳(tan)鋼(gang)為(wei)(wei)250℃;優質碳(tan)鋼(gang)(如10鋼(gang))為(wei)(wei)450℃.高(gao)壓(ya)管(guan)(guan)(guan)路(lu)(lu)(lu)均用(yong)優質碳(tan)鋼(gang)(20鋼(gang))制成的(de)(de)(de)無縫(feng)鋼(gang)管(guan)(guan)(guan),最高(gao)工作(zuo)溫度為(wei)(wei)200℃。
輸送強腐蝕性(xing)或高溫(wen)的介質時,采用不銹鋼、耐(nai)(nai)酸鋼或耐(nai)(nai)熱鋼制的無(wu)縫鋼管。這種無(wu)縫鋼管也可(ke)用熱軋(ya)而成(cheng)或再冷拔(ba)成(cheng)尺寸較小的管子。熱軋(ya)管的規格:外(wai)徑為(wei)6~89mm,壁(bi)厚(hou)為(wei)1~7mm,長度(du)為(wei)1.5~7m.耐(nai)(nai)熱鋼管最高工作溫(wen)度(du)為(wei)850℃。
輸送高壓(ya)水時(shi),可以采(cai)用厚壁無縫鋼(gang)管,它(ta)的外徑為(wei)12~219mm,壁厚為(wei)3.5~40mm,長度為(wei)3~4m,最高工作溫(wen)度為(wei)375℃。
2. 鑄鐵管
鑄鐵(tie)管(guan)(guan)分為普通(tong)鑄鐵(tie)管(guan)(guan)和硅鐵(tie)管(guan)(guan)兩類。
①. 普通(tong)鑄鐵(tie)管(guan)
一般用灰口(kou)鐵鑄造,耐蝕性好,但質脆(cui),不抗沖擊(ji)。常用于埋地(di)給(gei)水(shui)管(guan)(guan)(guan)道、煤氣管(guan)(guan)(guan)道和(he)(he)室內(nei)排水(shui)管(guan)(guan)(guan)道。給(gei)水(shui)鑄鐵管(guan)(guan)(guan)有(you)低壓(p=0.45MPa)、常壓(p=0.75MPa)和(he)(he)高壓(p=1MPa)三種(zhong),直徑50~1500mm,壁厚7.5~30mm,管(guan)(guan)(guan)長(chang)3m、4m、6m.管(guan)(guan)(guan)端形狀分(fen)承(cheng)插(cha)式和(he)(he)法蘭式兩種(zhong),其(qi)中以承(cheng)插(cha)式最(zui)常用。
排(pai)水鑄(zhu)鐵(tie)(tie)管只有承插式一種。直徑(jing)50~200mm,壁厚4~7mm,長度(du)有0.5m、1m、1.5m、2m等多種,但一般為2m。排(pai)水鑄(zhu)鐵(tie)(tie)管比(bi)給水鑄(zhu)鐵(tie)(tie)管壁薄,承口(kou)也淺,使用時可根據外形(xing)加以判別。
②. 硅鐵管
可分(fen)為高硅(gui)(gui)鐵(tie)管(guan)和(he)抗(kang)(kang)氯(lv)硅(gui)(gui)鐵(tie)管(guan)兩(liang)種。高硅(gui)(gui)鐵(tie)管(guan)能抵(di)抗(kang)(kang)多種強酸的(de)(de)腐(fu)蝕(shi),而含鉬(mu)的(de)(de)抗(kang)(kang)氯(lv)硅(gui)(gui)鑄(zhu)鐵(tie)可抵(di)抗(kang)(kang)各種濃(nong)度(du)和(he)溫度(du)的(de)(de)鹽酸,因此是很好的(de)(de)耐(nai)腐(fu)蝕(shi)管(guan)材。高硅(gui)(gui)合金鑄(zhu)件硬度(du)大,只能用(yong)金剛砂輪修磨或用(yong)硬質合金刀具來(lai)加工。高硅(gui)(gui)合金制(zhi)件受到輕微敲(qiao)擊(ji)、局部受熱或急劇(ju)冷(leng)卻時,皆易破裂,但是由于(yu)其耐(nai)腐(fu)蝕(shi)性好,所以廣泛應用(yong)于(yu)化工管(guan)路(lu)中。
高硅鑄鐵(tie)(tie)管(guan)(guan)和抗氯(lv)硅鑄鐵(tie)(tie)管(guan)(guan)的(de)(de)(de)內(nei)徑(jing)為32~300mm,壁厚(hou)為10~16mm,長(chang)度為150~2000mm.用(yong)于輸送公稱壓(ya)力低于0.25MPa的(de)(de)(de)腐蝕性(xing)(xing)介質。硅鐵(tie)(tie)管(guan)(guan)的(de)(de)(de)耐熱性(xing)(xing)能(neng)好,可達900℃.硅鐵(tie)(tie)管(guan)(guan)的(de)(de)(de)兩端有供(gong)連(lian)接用(yong)的(de)(de)(de)凸肩(jian),利(li)用(yong)對開式的(de)(de)(de)松套法蘭(lan)連(lian)接。
3. 紫銅(tong)管和黃銅(tong)管
紫銅管(guan)和黃銅管(guan)都是拔制(zhi)(zhi)或(huo)擠制(zhi)(zhi)而成的無(wu)縫管(guan),主要用于制(zhi)(zhi)造換熱設(she)備(bei)、制(zhi)(zhi)氧設(she)備(bei)中(zhong)的低溫管(guan)路(lu)以及機械設(she)備(bei)中(zhong)的油(you)管(guan)和控制(zhi)(zhi)系統(tong)的管(guan)路(lu)。
拔制紫銅(tong)(tong)(tong)管(guan)(guan)外(wai)徑(jing)為(wei)3~360mm,壁厚(hou)為(wei)0.5~10mm;壓(ya)制紫銅(tong)(tong)(tong)管(guan)(guan)外(wai)徑(jing)為(wei)30~280mm,壁厚(hou)為(wei)5~30mm.管(guan)(guan)長均為(wei)1~6m,隨(sui)管(guan)(guan)子外(wai)徑(jing)與制造(zao)方法而(er)異。拔制的盤狀紫銅(tong)(tong)(tong)管(guan)(guan)直徑(jing)較小,每盤管(guan)(guan)子長度從十幾米至數十米,黃(huang)銅(tong)(tong)(tong)管(guan)(guan)外(wai)徑(jing)為(wei)3~195mm.當工作溫(wen)度高于250℃時(shi),不宜在壓(ya)力下(xia)使(shi)用紫銅(tong)(tong)(tong)管(guan)(guan)和黃(huang)銅(tong)(tong)(tong)管(guan)(guan)。紫銅(tong)(tong)(tong)管(guan)(guan)和黃(huang)銅(tong)(tong)(tong)管(guan)(guan)可以采用焊(han)接(jie)連(lian)接(jie)、法蘭連(lian)接(jie)和螺紋連(lian)接(jie)。
4. 鋁(lv)管
鋁(lv)(lv)(lv)管(guan)(guan)(guan)(guan)是拔制而成的無縫鋁(lv)(lv)(lv)管(guan)(guan)(guan)(guan),它主(zhu)要用來輸送濃硝酸(suan)、醋酸(suan)、甲(jia)酸(suan)及其他介質,但不(bu)能抗堿液(ye)。鋁(lv)(lv)(lv)管(guan)(guan)(guan)(guan)外徑為6~120mm,壁厚(hou)為1~10mm,管(guan)(guan)(guan)(guan)長可達6m.當工作溫度高于160℃時,不(bu)宜在壓力下使用鋁(lv)(lv)(lv)管(guan)(guan)(guan)(guan)。鋁(lv)(lv)(lv)管(guan)(guan)(guan)(guan)的連接(jie)采用焊接(jie)連接(jie)和法(fa)蘭連接(jie)。
5. 鉛管
鉛(qian)管(guan)(guan)對硫酸(suan)(suan)具有良好的耐蝕性,因此(ci)廣(guang)泛應用(yong)于(yu)(yu)硫酸(suan)(suan)工業中,但(dan)由于(yu)(yu)鉛(qian)管(guan)(guan)有強度低(di)、密(mi)度大(da)、抗熱性能差等缺點,故近(jin)來已(yi)逐漸被(bei)各種(zhong)耐酸(suan)(suan)合金(jin)管(guan)(guan)與(yu)塑料管(guan)(guan)所代替。鉛(qian)管(guan)(guan)的內(nei)徑為(wei)8~150mm,壁厚為(wei)2~10mm.內(nei)徑小于(yu)(yu)55mm的鉛(qian)管(guan)(guan)多(duo)制(zhi)成(cheng)盤管(guan)(guan),內(nei)徑大(da)于(yu)(yu)60mm時才做成(cheng)直管(guan)(guan),每根長2~2.5m.由于(yu)(yu)鉛(qian)易于(yu)(yu)輾(zhan)壓、鍛制(zhi)和焊接,所以(yi)大(da)直徑的鉛(qian)管(guan)(guan)很容(rong)易用(yong)鉛(qian)板焊制(zhi)而成(cheng);也可以(yi)在鉛(qian)中加入8%~10%的銻,而形成(cheng)鉛(qian)銻合金(jin),此(ci)合金(jin)通常稱(cheng)為(wei)硬鉛(qian),它可用(yong)于(yu)(yu)鑄造鉛(qian)管(guan)(guan)。
鉛管的連接可采用(yong)焊(han)接連接和法蘭連接。工作(zuo)溫(wen)度高于140℃時,就不宜在(zai)壓力下使用(yong)鉛管。