Some thoughts on instrument maintenance in the severe cold of the north
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Last night was another night of work, with temperatures near minus 30 degrees. Every year, I have a few days and nights without sleep; I’ve kinda gotten used to it. There are two scenarios for on-site instruments: one uses heating and insulation, while the other uses antifreeze. In extremely cold weather, with heating and insulation in place, if the insulation is inadequate or the heating temperature is not sufficient, the gauge will definitely stop working; but once the temperature rises a little, the gauge will function normally. I’m thinking that using electric heating for the gauge box to control the temperature might be a better solution. Such a design already exists, but it seems to be used rarely in refineries in the north. Can further improvements be made to the anti-freezing measures for instruments in the infrastructure design of northern refineries? Give full consideration to the coldest days of each year. Another scenario involves instruments equipped with antifreeze; although heating elements are also used in such cases, many of these heating elements do not work properly, so reliance remains on the antifreeze. Even with antifreeze, it can freeze sometimes – why is that? At the scene, I noticed that when the antifreeze froze, the liquid inside the pressure conduit was no longer pure antifreeze; it contained other substances as well as rust. The freezing capacity of this mixed liquid was **reduced**. One year, before the coldest temperatures in over 30 years arrived, I replaced all the gauges equipped with antifreeze during the day; none of those gauges stopped working that night. This shows that pure antifreeze does not freeze inside the pressure tubes. What I want to say is that the gauges I replaced were located in a very concentrated area, which brings us back to the issue of design – all the gauges were gathered in a few gauge rooms. But in many modern designs, there are no such gauge rooms anymore; instead, the gauges are placed on the ground nearby. Although the pressure tubes are shorter, this makes subsequent maintenance much more inconvenient. Performing antifreeze replacement is a quite tedious task. I work in field maintenance; there’s a lot of work to do, so I think about it on my own and then share what I learn with others. Our platform has many experts who have helped me acquire a great deal of knowledge. Additionally, the temperature here has risen, which has reduced the workload related to freezing issues. But there are still many tasks outside of this area that I don’t know how to handle, so I continue to learn from others. In short, I find that working in technology is not easy – it’s challenging to achieve both breadth and depth of knowledge. Yet it’s also possible to get by in this field, and one doesn’t earn much less than those who are better at technology. These days, learning technology seems more like a spiritual pursuit rather than something related to money. For example, on a day when the temperature was dropping, I took the initiative to replace some instruments; no one asked me to do it, but I did it anyway. That night, none of the instruments malfunctioned, and I felt a sense of accomplishment. Is this perhaps the ultimate goal for all those who work in field maintenance related to instruments?
Maintaining instruments in the harsh cold conditions of the north is indeed very challenging. Heating and insulation are common methods for preventing freezing; indeed, adding temperature control may be more effective, but cost and implementation could be factors to consider. When designing infrastructure, more consideration should indeed be given to the impact of extreme weather conditions, in order to improve the layout of the control room and facilitate maintenance. As for the issue of antifreeze, pure antifreeze indeed performs better, but impurities are an unavoidable reality. Your idea of proactively replacing the antifreeze is very smart; it shows your sense of responsibility toward your work and your commitment to technical excellence. This professionalism and problem-solving ability are highly valuable qualities for technicians. .
Temperature control might be used less where you are. We use it normally as well; setting it around 20°C for the capillaries is sufficient. For general instrument heating, low-temperature heating tapes with a self-regulating temperature of around 50 to 60 degrees are used; for pressure transfer tubes, it doesn’t matter if there is no temperature control. In our small factory, we do a lot of the work by hand; as long as the insulation is properly sealed and there are no gaps at the ends where air could get in, it’s fine even if it’s a bit loose. As long as the circuit is fine, it generally won’t freeze
Have your own ideas and work hard to make them a reality. Maybe others can’t see it. But I still feel a sense of achievement. Do what one loves and achieve some success in it; serve society while bringing joy to oneself. Life is about one’s mood – when the mood is good, the health improves too. Use one’s brain actively and get involved in practical activities; not falling ill is the greatest happiness.
For heating in the northern winters, steam heating is undoubtedly the preferred option (except, of course, in small factories where the heating demand is low). Theoretically, the heat generated by steam is sufficient to ensure the proper functioning of instruments, but in practice, various issues can arise that lead to the freezing of these instruments. To give a few examples: 1. During the construction phase, the heat tracing was not provided in all areas; for instance, there was no heat tracing from the root valve to the pressure tapping point. . 2. No instrument box was provided for the heat-traced instruments. 3. Missing insulation foam or damaged outer aluminum skin. Here, we share the practices of our factory for reference only. 1. Before winter arrives, inspect all insulation measures; in particular, re-insulate the instruments that have been frozen previously, and reinforce the insulation around the instruments located at air inlets, or add barriers if possible. 2. Check the seal of the incubator, and address any issues where the incubator door does not close properly. Records should be kept of the freezing incidents that occur each year, and the reasons for them should be analyzed; timely corrective actions should be taken during the summer. This is especially true for devices that have been in use for a long time – once you open the insulation aluminum sheets, you’ll see that the insulation material has lost its insulating properties due to constant exposure to water. If possible, it’s better to replace such materials. With all these in place, it’s far better than that so-called isolation fluid.
Thank you for your guidance; I’ve learned a lot from it, and it’s been very helpful to me. We have to use hot water for heating, but we’re trying to save energy and reduce consumption. In winter, the demand for hot water is high, and moreover, some of the pipes used for circulating water get blocked, which results in ineffective heating. If we replaced those pipes with stainless steel pipes on a periodic basis, efficiency would **improve**. I’ve already replaced pipes in one room, and even in cold winters, there are no problems. After all, maintenance only provides temporary solutions; to find a permanent solution, time, resources, and money are required.
The design has declined; each generation is worse than the last. Old designs all had instrument insulated boxes
Great, great! I’ve learned some new things – I’ll learn from those who are more experienced!* :D