Regularmaintenance常规保养willinvolveattentiontolubricationoftheshaftbearingandensuringthattheshaftsealorglandisnotleakingliquid.Unsatisfactoryoperation运转不良orlossofperformance性能下降mayrequireminorormajoroverhauls.Commonfaults故障,suchasnodischarge,maybearesultofvalvesinthesystembeingshut关闭;suctionstrainersblocked堵塞orotherfaultsoccurringintheprimingsystem.Airleaksinthesuctionpiping,achoked阻塞impellerortootight过紧的ashaftglandcanallleadtopoorperformance性能恶化.Whendismantling拆卸thepumptoremove移开thepumpingelement,anyprimingpipes引水管orcoolingwatersupplypipesmustbedisconnected断开连接.Inmodernpumpswithcouplingspacer耦合装置,theimpeller叶轮andshaft轴canbereadilyseparated分离forexamination.Theshaftbearingbush轴承套togetherwiththecasing泵壳andimpeller叶轮shouldbeexaminedforwear磨损.Duringthepumpoperation,asthewatermasspassesfromeyeoftheimpellertowardsitsperiphery,itcreatesvacuum真空attheeyeoftheimpellerandinsidethesuctionpipe.Ifthetemperatureofthepassingwaterhappenstobehigherthanthesaturationtemperature饱和温度ofthewaterattheprevailingvacuum普通真空,someofthewatermayevaporate蒸发toformtinyvaporbubbles气泡,whichtravelthroughtheimpeller.Aspressurerises，thevaporinthetinybubblesbecomesunstableandcondenses冷凝backtoliquidcausingsmallimplosions内爆inthesebubbles.Theseimplosionshaveenoughenergytocausepitting点蚀intheadjoining邻近的materialoftheimpelleraswellasthepumpcasing.Thisprocessofimpellerandthecasingmaterialwastage损耗iscalledcavitation气蚀.Theonlyremedy解决方法topreventcavitationistoensurethatthetemperatureofthewaterpassingthroughthesuctionpipeandtheeyeoftheimpellerismaintainedbelowthesaturationtemperatureattheprevailingvacuum.Apartfromthat,theinnersurfaceofthecasingmaybecoated上涂层withhardepoxylayer环氧树脂层tominimizetheeffect