How to prevent pipelines from freezing in heavy snow?
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This year, the whole country experienced rare heavy snow and low temperatures, causing pipes to freeze and crack in many areas. In this situation, how is freezing protection applied to ordinary pipes, and which pipes require such protection? Also, when the local temperature drops to as low as -10 degrees in winter, does the pipeline need insulation to prevent freezing? If the lowest temperature in winter is -10 degrees, do the pipes need insulation to prevent freezing? Should extreme weather temperatures be taken into account in pipeline design? For example, this year there was a sudden drop in temperature, and pipes in many places cracked from the cold.
Pipelines should be prepared in advance for sudden temperature drops. When insulation is present and the liquid medium inside the pipeline is at room temperature, it is necessary to maintain flow so that the temperature inside the pipeline does not drop sharply enough to cause freezing, which could lead to pipe rupture!
If the pipeline is not insulated, but the fluid inside it remains in flow, the pipeline shouldn’t freeze and crack, right?
There are many ways to do this: 1. Burying the pipes, which helps maintain heat; 2. Installing insulation layers; 3. Using heat tracing for the pipes. In any case, in northern regions, measures must be taken for pipes that may freeze
If the temperature in the area where the north and south meet drops to around -10 degrees or lower, is it necessary to take anti-freezing measures when designing the pipelines in such conditions?
:Q: For those that are sensitive to cold, and for whom freezing can lead to serious consequences, that certainly needs to be taken into consideration. But if it’s just a few meters long of water pipe, then it doesn’t matter much
In case of abnormal weather conditions, we should take anti-freezing measures. For water drainage pipelines that are not used in normal production, backflow should be enabled appropriately to prevent freezing. For flowing cryogenic media, it is best to increase the flow rate. It is best to operate at high load during production. For immobile, freeze-prone media, it is best not to have them in outdoor pipes; if they are present, it is advisable to empty them to prevent the pipes from cracking due to freezing. In short, allowing the material to flow is a anti-freezing measure, and allowing the material to be emptied is also an anti-freezing measure; it depends on which one is suitable for your pipeline.
Should extreme weather conditions in the area, such as temperatures that occur once every few decades or once in 100 years, be taken into consideration in future designs? Doesn’t that mean that in many places, anti-freezing measures need to be taken into account in the design of pipelines?
The fundamental reason for the rupture of frozen tubes is that the stress properties of the tube material itself – such as hoop stress, elastic modulus, and Poisson’s ratio – are not sufficient to withstand the stress resulting from the volume expansion caused by water freezing, leading to rupture. The selection of pipe specifications can be done once and for all; the problem is that pipes suitable for low-temperature outdoor conditions are very expensive. This is a question that both the designer and the user need to consider.
Northeast electric heating, North steam heating
I’m not sure what measures should be taken to insulate overhead pipelines for natural gas and coke oven gas, especially when temperatures drop below -10 degrees Celsius. I would appreciate the advice from the experts upstairs.
If economic factors need to be taken into account in the design, can the local minimum average temperature be used as a guide in the actual design? I’m not sure if this design is reasonable
I think in addition to heat tracing, it is necessary to find solutions from a process perspective, such as addressing the issue of once-in-50-years cold waves in the south by raising the liquid temperature and increasing the flow rate
The best approach is to maintain fluid flow; if that doesn’t work, the flow rate can be increased.
Insulation and heat tracing are probably not very economical; it would be better to increase the flow rate and maintain fluid movement
Install heat tracing at those parts within the station where valves are prone to ice blockage during throttling – such as pressure regulators. A few days ago, due to the drop in temperature, our company handled several pressure regulators in this way; the results were good, ensuring normal operations in all production areas of the Chuan Dong Gas Mine. For overhead pipelines, insulation measures are not applied in half of the cases, aside from the process requirements.