卡城华人工程师论坛 - Q&A:why discharge close for single-stage Centri.pumpstart,but open for multi

>> 欢迎您，客人：登录 | 注册 | 忘记密码 | 在线 | 搜索 | 帮助

您正在浏览卡城信息中心

	卡城新闻社区消息即时新闻加国新闻加西新闻爱城新闻萨省新闻焦点杂谈回国发展军事天地体坛纵横海外文摘加中贸易情感画廊保健美食女人话题难得一笑音乐诗画时尚秀吧爱城生活网站建议工程交流
	加西论坛移民茶馆加西商机留学生涯温馨生活少儿乐园原创精华精华转贴加西热贴生活导航精华诗苑摄影集锦网庆征文地产知识站务公告萨城论坛里贾纳坛大温世界山东同学天津同乡艺术中心风筝专辑
	信息中心房屋租赁旧车买卖二手家具电器电脑日用商品求职招聘电脑红娘定居指南生活咨询城市介绍房屋市场车来车往精华旅游移民协会学生学者专家协会中药协会江浙上海加中商会原创视频其它信息

點擊轉換 繁體中文 論壇

　卡尔加里信息中心论坛
　卡城华人工程师论坛　[返回]
　　Q&A:why discharge close fo ...　
标记论坛所有内容为已读　
>> 卡城华人工程师论坛欢迎您的到来 <<

　　 ◆您是本帖第 528 个阅读者◆　　　　

* 贴子主题： Q&A:why discharge close for single-stage Centri.pumpstart,but open for multi　　把本贴打包邮递

max123
　　

信息: 该用户目前不在线
威望: 0
来自: 保密　
总发贴数: 1 篇
注册日期: 2005/02/04

消息　查看　搜索　好友　邮件　复制　引用　回复贴子回复　

Q:BASICS OF CENTRIFUGAL PUMP OPERATION TELL US THAT PUMPS HAVE TO BE STARTED WITH DELIVERY VALVE OF PUMP IN FULLY CLOSED CONDITION.HOWEVER.SOME OF THE MULTISTAGE PUMP MANUFACTURES ADVISE THAT MINIMUM DISCHARGE IS TO BE ENSURED AT ALL TIMES(INCLUDING STARTING TIME) AND DELIVERY VALVE SHOULD NEVER BE FULLY CLOSED.WILL SOMEBODY EXPLAIN THIS CONTRACTION?

A: While starting a pump with the discharge valve closed is easier on the motor and allows for a more controlled start-up, it can be hard on a pump, causing additional radial force on the shaft as well as heat build-up. In a single stage pump these affects will probably not cause harm in the time it takes for the Operator to begin opening the valve.

A multistage pump, with the greater heat input and bearing span(greater shaft flexibility), will be much more sensitive to the conditions mentioned above. Depending on the number of stages and fluid being pumped, damage due to component rubbing or gassing up of the pump can happen very quickly during no flow operation.

Starting pumps with the discharge valve cracked open is probably better for most pumps, but will be more critical for multistage types.

　　2005/02/02 00:04am　IP: 已设置保密

该主题只有一页