[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"$fL9ElQQx_GLs3-nP-EcuGWnWMc7D685Uo1qkztYb2eX4":3},{"answer":4,"createTime":5,"id":6,"options":7,"origin":12,"question":19,"related":20,"source":30,"type":31},[],"2023-12-18 23:45:28",115812887,[8,9,10,11],"the mechanical seal","packed stuffing boxes","either A or B","neither A nor B",{"count":13,"courseId":14,"courseImg":15,"courseName":16,"workId":17,"workName":18},10,"387be972678c6b7c964b909f59deaab6","https:\u002F\u002Ftihai-oss-cloud.itihey.com\u002Fimg\u002Fb352afbc1ea29fbb6d8c348e7b56bb46.jpg","轮机英语","42393c376deb419398ae28899790f518","船用泵4","Shaft sealing in a centrifugal pump can be affected by _____",[21,32,39,48,51,60,69,77,86,95],{"answer":22,"createTime":5,"id":23,"options":24,"question":29,"source":30,"type":31},[],115812880,[25,26,27,28],"cavitation","water hammer","fluid friction","steam knock","Reduced capacity, accompanied by vibration and noise at the suction of a centrifugal pump is a result of____","v1",0,{"answer":33,"createTime":5,"id":34,"options":35,"question":38,"source":30,"type":31},[],115812882,[36,37,10,11],"valves in the system being shut","suction strainers blocked","Common faults with centrifugal pumps, such as no discharge, may be a result of _______",{"answer":40,"createTime":5,"id":41,"options":42,"question":47,"source":30,"type":31},[],115812884,[43,44,45,46],"Close radial clearance between impeller hub and casing","Low rotational speed of impeller","Removable end plate","Replaceable impeller and casing wear rings","Which feature of a centrifugal pump reduces the need for renewing worn impellers and pump casings",{"answer":49,"createTime":5,"id":6,"options":50,"question":19,"source":30,"type":31},[],[8,9,10,11],{"answer":52,"createTime":5,"id":53,"options":54,"question":59,"source":30,"type":31},[],115812888,[55,56,57,58],"non-pulsating","pulsating","positive","non-positive","Centrifugal pumps are popular because they are very simple in construction, and produce smooth, constant, _____ discharge",{"answer":61,"createTime":5,"id":62,"options":63,"question":68,"source":30,"type":31},[],115812890,[64,65,66,67],"motor controller overload would open","pump would eventually overheat","relief valve would continuously cycle open","motor would overheat","If a centrifugal pump were continually operated with the discharge valve closed, the _____",{"answer":70,"createTime":5,"id":71,"options":72,"question":76,"source":30,"type":31},[],115812892,[25,73,74,75],"electrolysis","abrasion","friction","Pitting in the suction areas of a centrifugal pump bronze impeller is usually caused by _____",{"answer":78,"createTime":5,"id":79,"options":80,"question":85,"source":30,"type":31},[],115812894,[81,82,83,84],"noise and vibration","an increase in discharge pressure","an increase in suction pressure","lifting of the relief valve","The usual symptoms of cavitation in a centrifugal pump is _____",{"answer":87,"createTime":5,"id":88,"options":89,"question":94,"source":30,"type":31},[],115812897,[90,91,92,93],"closed","opened fully","cracked open","partly open","When starting a centrifugal pump, the discharge valve should be ____",{"answer":96,"createTime":5,"id":97,"options":98,"question":103,"source":30,"type":31},[],115812901,[99,100,101,102],"shaft and impeller","motor and pump shaft","casing and impeller wearing rings","lantern ring and impeller","To maintain design discharge pressure from a centrifugal pump, the design clearance must be maintained between the _____"]