鉛(qian)管因(yin)質(zhi)軟且重,故(gu)經過搬運、裝(zhuang)卸之(zhi)后(hou)一般均產生變(bian)形,所以(yi)鉛(qian)管在安裝(zhuang)前均應調直(zhi)和校圓(yuan)。 


  鉛(qian)(qian)管(guan)調直(zhi)(zhi)時,鉛(qian)(qian)管(guan)應放(fang)在(zai)鋪有木板的平臺(tai)上用木榔頭輕輕敲打(da)調直(zhi)(zhi)。為(wei)了便于檢査和操作,常把鉛(qian)(qian)管(guan)緊貼(tie)在(zai)角(jiao)鋼或槽鋼內側(ce)的翼上,根據管(guan)子和型鋼的間隙拍打(da)調直(zhi)(zhi)。


  鉛(qian)管(guan)(guan)除調直外(wai)(wai),還需(xu)校(xiao)圓。直徑(jing)大于DN50mm的(de)鉛(qian)管(guan)(guan)校(xiao)圓,可用一(yi)根(gen)外(wai)(wai)徑(jing)小于鉛(qian)管(guan)(guan)內徑(jing)的(de)鋼管(guan)(guan)(管(guan)(guan)端(duan)最好制(zhi)成一(yi)半球形封(feng)頭(tou))穿(chuan)在鉛(qian)管(guan)(guan)內,并把(ba)鋼管(guan)(guan)的(de)兩端(duan)放在支撐架上, 然(ran)后用木錘敲打鉛(qian)管(guan)(guan)被壓扁(bian)的(de)地(di)方,邊(bian)打邊(bian)轉動(dong)管(guan)(guan)子,直到(dao)將(jiang)管(guan)(guan)子校(xiao)圓為止。


  鉛(qian)(qian)管校圓(yuan)的方(fang)法還有用(yong)硬木(mu)制成的外(wai)徑(jing)與鉛(qian)(qian)管內(nei)徑(jing)相同的圓(yuan)柱形胎具(ju)(ju),將頭部(bu)削圓(yuan), 穿上(shang)繩子(zi),用(yong)繩將胎具(ju)(ju)拉進管內(nei),使變形部(bu)位隨(sui)胎具(ju)(ju)而撐圓(yuan)。


  鉛(qian)管(guan)直徑不大于DN50mm的(de)鉛(qian)管(guan)校(xiao)圓(yuan),可(ke)將鉛(qian)管(guan)兩端(duan)堵塞,在管(guan)內通(tong)入壓(ya)力為0.3~0.4MPa的(de)壓(ya)縮(suo)空(kong)氣,然后(hou)用焊(han)炬對壓(ya)扁的(de)地方(fang)加(jia)熱,管(guan)內的(de)壓(ya)縮(suo)空(kong)氣把(ba)管(guan)子脹(zhang)圓(yuan),加(jia)熱時,要注意使加(jia)熱部分受熱均(jun)勻(yun),升(sheng)溫不要太快,當管(guan)子被脹(zhang)圓(yuan)時,應(ying)立即停(ting)止加(jia)熱。