在线 | 一区二区三区四区-在线 v亚洲 v欧美v 专区-在线 成人-在线 丝袜 欧美 日韩 制服-女性影院-欧乱色国产精品兔费视频

Contact Us   
Search   
Your Position: Home > News & Events > Industry News

ball valve development process

2013/11/10      view:

The advent in the 1950s, cast steel ball valve With the rapid development of science and technology, continuous improvement of the production process and product structure, in just 40 years, it has rapidly developed into a main valve class.

In the industrially developed countries of Western countries, the use of the ball valve is gradually on the increase in China, the ball is widely used in petroleum refining, long-distance pipeline, chemical, paper, pharmaceutical, water conservancy, electricity, municipal, and steel industries. occupies a pivotal position in the national economy. Ball valves only need to turn the operation of 90 degrees and a small torque can be closed tightly. Full equality body cavity of the media to provide a little resistance, through the flow channel. Usually considered the most suitable valve opening and closing done directly, but recent developments have sent the ball valve is designed so that it has a throttle and control the flow purposes. The main features of valve is its own compact, easy operation and maintenance, suitable for general working medium of water, solvents, acids, and natural gas, but also applies to the working conditions of media, such as oxygen, hydrogen peroxide, methane and ethylene. Ball valve can be a whole, it can be modular.Manually operated ball valves can be closed quickly and thus there is a danger of water hammer. Some ball valves are equipped with an actuator that may be pneumatically or motor operated. These valves can be used either for on/off or flow control. A pneumatic flow control valve is also equipped with a positioner which transforms the control signal into actuator position and valve opening accordingly.

主站蜘蛛池模板: 欧美极品另类xxx | 欧美亚洲综合另类成人 | 色五月视频 | 天天搞天天操 | 免费被黄网站在观看 | 亚洲成网| www.99在线 | 午夜视频免费 | 色天天综合色天天看 | 性欧美日韩 | 影音先锋 色天使 | 久久精品久久久 | 成年人在线网站 | 亚洲国产成人精品不卡青青草原 | 亚洲成在人天堂一区二区 | 欧美aaaaaaaaa| 国产亚洲人成网站观看 | 欧美尺寸又黑又粗又长 | 色综合久久98天天综合 | 国产成人永久在线播放 | 国产精品莉莉欧美自在线线 | 亚洲乱码卡一卡二卡三永久 | 理论片国产| 午夜啪视频 | 国内精品久久久久影 | 久久精品高清视频 | sesese在线观看| 日本欧美一区二区三区不卡视频 | 高清午夜线观看免费 | 黄色三级在线观看 | 欧美不在线 | 色欲麻豆国产福利精品 | 国产精品天天看大片特色视频 | 68日本xxxxxxxxx18能看的 | 欧美人与动另类在线 | www.夜夜爽 | 窝窝午夜看片免费视频 | 一本到卡二卡三卡免费高 | 久久不射影院 | 天天摸夜夜摸夜夜狠狠摸 | 天天操夜夜爱 |