问题 问答题 简答题

运行中的离心泵都须检查哪些情况?

答案

参考答案:

(1)泵轴的温度,滑动轴承不大于65℃,滚动轴承不高于70℃。

(2)检查电机与泵运转情况,各部分的振动噪音及密封。

(3)检查各参数泵的出口压力、流量、电机的电流、电压。

(4)冷却水系统,油封系统。

(5)检查润滑系统。

单项选择题

Large companies need a way to reach the savings of the public at large. The same problem, on a smaller scale, faces practically every company trying to develop new products and create new jobs. There can be little hope of raising the money needed from friends and people we know, and while banks may agree to provide short-term finance, they are generally unwilling to provide money, for long-term projects. So companies turn to the public, inviting people to lend them money, or take a share in the business in exchange for a share in future interests. This they do by issuing stocks and shares in the business through the Stock Exchange. By doing so they can put into circulation the savings of single persons and institutions, both at home and abroad.

When the saver needs his money back, he does not have to go to the company with whom he originally placed it. Instead he sells his shares through a stockbroker to some other saver who is seeking to invest his money.

Many of the services needed both by industry and by each of us are provided by the government or by local organizations. Without hospitals, roads, electricity, telephones and railways, this country could not work. All these require continuous spending on new equipment and new development if they are to serve us properly, requiring more money than it is raised through taxes alone. The government, local organizations and nationalized industries therefore frequently need to borrow money to finance major capital spending, and they, too, come to the Stock Exchange.

There is hardly a man or woman in this country whose standard of living does not depend on the ability of his or her employers to raise money to finance new development. In one way or another his new money must come from the savings of the country. The Stock Exchange exists to provide a channel through which these savings can reach those who need finance.

All the basic services on which we depend are()

A. unable to provide for the needs of the population

B. financed wholly by rates and taxes

C. in constant need of financial support

D. run by the government or local organizations

单项选择题 案例分析题