久久精品一区二区三区日韩-久久精品一区二区三区四区-久久精品一区二区三区中文字幕-久久精品一区二区三区资源网-久久精品一区二区影院-久久精品伊人

Language

Introduction to fire resistance and installation precautions of regulating valve

1、 Importance of fire control valve

In chemical, petroleum and other automation systems, in case of fire, if some equipment in the system can cut off the access of combustible fluid to the fire environment in time, the heavy losses caused by the direct spread of fire from the fire area to the plant area can be avoided. The regulating valve is an important part of the automation system. It is installed in the field control flow channel. Therefore, cutting off the flow channel is the main equipment to prevent fire caused by combustible fluid. In case of fire, the switch is the key. Since the regulator is controlled by the regulator in the control room and is not manually operated, the main characteristics of the fire damper [door should be that it can withstand temperature regulation and short-term operation, or the leakage should be very small when closed. The flame retardant performance of the valve should be regarded as a very important issue to be considered, hoping to attract the attention of relevant personnel.

2、 Fire protection standard for regulating valve

What kind of valve is a fire damper? Fire dampers mentioned abroad (fire safety valve), there are many and inconsistent definitions of valve fire resistance in foreign countries, and this definition is still lack of clear provisions in the industry. So far, there is no single test or specification to determine whether the valve is fire resistant. Many industrial associations, oil companies, insurance companies, valve manufacturers and authorities in the UK and the United States have stipulated various test methods. However, to be tested The type and main test specifications of the test valve vary according to the test method. The debate on combustion valve test continues. Some people try to synthesize two or more methods into a complete method, but no decision has been made. How should I accurately define fire dampers? This is the problem we want to study. First, we need to study the standard of soft seat. It is believed that metal gate valves and globe valves will not melt in a fire and are fire dampers. These valves are designed and constructed to ensure metal to metal contact before and after a fire, thereby preventing combustible liquids from entering the fire. However, metal seats do not seal well when operated before fire. The amount of leakage is so small that it is allowed in most established fire standards.

3、 Precautions for installation of regulating valve

Confirm that the pipeline is clean:

Foreign matters in the pipeline may damage the sealing surface of the valve, or even hinder the movement of the slide valve, ball or disc, resulting in the failure of the valve to close normally. To eliminate the possibility of minor hazards, clean all piping before installing the valve. Confirm that pipe dirt, metal debris, welding slag and other foreign matters have been removed. In addition, check the pipe flange to ensure that its gasket surface is smooth. If the valve has threaded ends, apply high-grade pipe sealant to the external threads of the pipe. Do not apply sealant to the internal threads, as excess sealant will be squeezed onto the internal threads of the valve body. Too much sealant will cause the valve core to block or dirt to accumulate, resulting in the failure of the valve to close normally.

Check the regulating valve

Although the valve manufacturer has taken some measures to prevent transportation damage, such damage may occur and can be detected and reported before installation. Do not install valves that are damaged during transportation or storage. Before installation, check and remove all shipping stops, protective plugs or gasket surface covers, and check the inside of the valve body to ensure that there is no foreign matter.


主站蜘蛛池模板: 荡女人人爱np粗口 | 久久网国产 | 日本在线小视频 | 欧美操操操操 | 伊人久久99亚洲精品久久频 | 成人激情小视频 | 久久精品久久精品久久 | 国产精品网址你懂的 | 国产亚洲亚洲精品777 | 久草在线2 | 久久精品免视看国产陈冠希 | 亚洲国产一 | 狠狠干人人插 | 日本精品在线观看视频 | 黄色成人毛片 | 天天视频一区二区三区 | 亚洲你我色 | 天天操欧美 | 亚洲图片综合区 | 欧美激情高清免费不卡 | 亚洲一区二区三区免费在线观看 | 久久久久久久99精品免费观看 | 黄色片在线免费观看视频 | 久久成人免费播放网站 | 国产午夜精品理论片久久影视 | 欧美一区二区手机在线观看视频 | 精品视频一二三区 | 91婷婷色涩涩 | 图片专区亚洲 欧美 另类 | 愉拍自拍| 综合久久一区二区三区 | 成人区精品一区二区不卡亚洲 | 91精品国产免费自在线观看 | 精品国产品香蕉在线观看 | 99久久精品免费看国产交换 | 精品国产一区二区麻豆 | 国产在线综合视频 | 日日夜夜亚洲 | 污网站视频在线观看 | 久久国产精品久久久久久久久久 | 午夜影院一级片 |