问题 问答题 简答题

管路设计及安装的一般原则。

答案

参考答案:

(1)管道应平行敷设,尽量走直线,少拐弯,少交叉,以求整齐方便。

(2)管子应尽量集中敷设,在穿过墙壁和楼板时,更应注意。

(3)并列管道上的管件与阀件应错开安装。

(4)管道应尽可能沿厂房墙壁安装,管与管间及管与墙间的距离,以能容纳活管接或法兰,以及进行检修为度。

(5)管道离地的高度以便于检修为准,但通过人行道时,最低点离地不得小于2m,通过公路时,不得小于4.5m,与铁路铁轨面净距不得小于6m,通过工厂主要交通干线一般标高为5m。

(6)管道上的焊缝不应设在支架范围内,与支架距离不应小于管径,但至少不得小于200mm,管件两焊口间的距离亦同。

(7)管道穿过墙壁时,墙壁上应开预留孔,过墙时,管外加套管。套管与管子的环隙间应充满填料,管道穿过楼板时亦相同。

(8)在焊接或螺纹连接的管道上应适当配置一些法兰或活管接,以便安装拆卸和检修。

(9)穿过墙壁或楼板间的一段管道内应避免有焊缝。

(10)阀件及仪表的安装高度主要考虑操作方便和安全。下列数据供参考:阀门(球阀,闸阀及旋塞等)1.2m,安全阀2.2m,温度计1.5m,压力表1.6m。如阀件装置位置较高时,一般管道标高以能用手柄启闭阀门为宜。

(11)坡度:气体及易流动物料的管道坡度一般为3/1000~5/1000,粘度较大物料的坡度一般为≥1%。

(12)管道各支点间的距离是根据管子所受的弯曲应力来决定,并不影响所要求的坡度,有关热损失和保温层厚度可按书中的表数据来计算。

(13)输送冷流体(冷冻盐水等)管道与热流体(如蒸汽)管道应相互避开。

(14)管道应避免经过电机或配电板的上空,以及两者的附近。

(15)一般的上、下水管及废水管宜采用埋地敷设,埋地管道的安装深度应在冰冻线以下。

(16)地沟底层坡度不应小于2/1000,情况特殊的可用1/1000。

(17)地沟的最低部分应比历史最高洪水位高500mm。

(18)真空管道应采用球阀,因球阀的流体阻力小。

(19)压缩空气可从空压机房送来,而真空最好由本车间附近装置的真空泵产生,以缩短真空管道的长度。用法兰连接可保证真空管道的紧密性.。

(20)长距离输送蒸汽的管道在一定距离处安装疏水器,以排除冷凝水。

(21)陶瓷管的脆性大,作为地下管线时,应埋设于离地面0.5m以下。

阅读理解

Once there was a piano player in a bar (酒吧). People came just to hear him play. But one night, a lady asked him to sing a song.

“I don’t sing,” said the man.

But the lady told the waiter, “I’m tired of listening to the piano. I want the player to sing!”

The waiter shouted across the room, “Hey, friend! If you want to get paid, sing a song!”

So he did. He had never sung in public before. Now he was singing for the very first time! Nobody had ever heard the song Mona Lisa sung so beautifully!

He had talent(天赋) he was sitting on! He may have lived the rest of his life as a no-name piano player in a no-name bar. But once he found, by accident, that he could sing well, he went on working hard and became one of the best-known singers in the US. His name was Nat King Cole.

You, too, have skills and abilities. You may not feel that your talent is great, but it may be better than you think. With hard work, most skills can be improved. Besides, you may have no success at all if you just sit on your talent.

小题1:The lady asked the player to sing a song because ________.

A.she had paid him for this

B.she knew him very well

C.she was tired of listening to the piano.

D.she enjoyed his singing小题2:Nat King Cole succeeded because ________.

A.the lady helped him a lot

B.he caught the chance(机会)

C.he continued to play in the bar

D.he played the piano well小题3:The words “sit on” in the passage probably mean “________”.

A.fail to realize

B.forget to use

C.try to develop

D.manage to show小题4:From the story we know if you have some talent, you should __________.

A.hide it and wait

B.ask others for help

C.pay no attention to it

D.work hard to improve yourself小题5:Which could be the best title(标题) for the passage?

A.Sing in the Bar

B.Achieve Success in Life

C.Never Lose Heart

D.Find Your Hidden(隐藏的) Talent

填空题