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.