【Please help vote for petrochemical events】Voting for the most valuable “information” (deadline: March 17)

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This post was last edited by Guan Gongyu on 2016-3-19 at 13:18. [Petroleum and Chemical Industry Activities] Voting for the most valuable “information” (deadline: March 17) http://bbs.hcbbs.com/thread-1568682-1-1.html (Source: Haichuan Chemical Industry Forum) [Petroleum and Chemical Industry Activities] Voting for the most valuable “information” (deadline: March 17); the best entries will be selected and posted separately for everyone to study and discuss. Event address: Who Would Have Thought? It’s Frozen Here Too (Reply for a big prize) http://bbs.hcbbs.com/thread-1543058-1-1.html Serial number, Author, Floor, Content, Presence of pictures: 1slll6113 Our light oil pipeline has also frozen at the pump inlet. This problem has not occurred for many years; it’s too cold this year. The oil is being supplied, but the demand on the other side is too low, so the flow rate is too slow and the oil freezes up during transportation. It’s really unexpected. 　 2 Xuefeng: 86.5 million. It was unexpected that the heating line associated with the heavy diesel return line froze. The temperature of the heavy diesel outlet line was 268 degrees, while the return temperature was 102 degrees; under normal conditions, the heating line should not freeze. The heating is intended only for use during winter shutdowns. No issues were detected during previous inspections, but it was found during a routine check that there was snow and ice accumulation on a section of the heating pipeline at the top of the tower. Inspections revealed that the heating for the return line of the heavy diesel fuel was combined with that of the overhead gas pipeline; the total length of this heating system was over 100 meters. Upon checking the inlet and outlet lines of the heating manifold, it was found that they were hot, yet the overhead part was frozen. The crude gasoline pipeline, designated as 3loveli1006, was also frozen – it’s hard to believe, right? In the catalytic crude gasoline distribution valve assembly, there is a line that leads to the tank for unqualified product; the crude gasoline simply wouldn’t be able to get out through that line. Eventually, the valves at both ends were closed and the flanges were removed, after which an ice column was found (with a diameter similar to that of the pipe, and about 50 cm long). How unfortunate! This issue is likely caused by water accumulation. On the outlet line of the wax oil feed pump at 4 Xuefeng 8617, there are diesel lines used for pump flushing. It was assumed that light diesel/aviation kerosene generally does not freeze, so these pipelines were left exposed without any heating or insulation. During winter maintenance of pumps, it is necessary to flush and replace the pump body. When it was found that the flow wasn’t working properly, it turned out that the entire pipeline had frozen – this was due to the lack of use over time, which caused water to accumulate in the pipelines and freeze. Immediately, heat tracing was added and insulation measures were taken. Most importantly, before winter arrives, it’s essential to open the lowest points of the pipelines to allow any accumulated water to drain out, so as to check for any remaining water. 5ht20070932: I didn’t expect the cooling tower to freeze so severely, nor did I expect the bypass valve for the coolant circulation to crack from freezing, nor did I expect the gasket in a section of the pipeline that was less than 5 cm wide to freeze and burst. As shown in Figure 6ht20070933, it was unexpected that the steam jacket inlet and outlet of the float level gauge froze; due to the high temperatures at noon, the pressure built up and caused an explosion. As shown in Figure 7, the corrosion inhibitor line for sinking ice 34 freezes; when heat is supplied, the operation becomes unstable, and without heat supply, freezing occurs ； The acid gas line has frozen; the design did not include any heating for insulation, so insulation was added later. Even with colder weather, it still freezes, and heating is now being installed. 　 On unit 8Happy First Line Drift 35, alkali solution ended up in the gas lines of the heating furnace. Due to delayed drainage, and coupled with the extreme weather conditions these past few days – with temperatures as low as minus 15 degrees – the alkali solution entered the gas lines used for maintaining the pilot light in the heating furnace, causing the pressure wires related to that pilot light to freeze. This led to low pressure in the pilot light, which in turn triggered the heating furnace’s safety mechanisms, and eventually caused the entire unit to enter safety mode. It took a whole day to resolve the issue. 96225687wwx36 These past few days have been quite abnormal; the circulating water tower froze, even though it usually doesn’t have any problems at such low temperatures in previous years. I’m in the south here; aside from steam pipes, there’s no need for any insulation at all. Yet now a third of the pipes in the factory have frozen up, which has forced production to stop. Even the water pumps with a capacity of 200 cubic meters per hour have had their outlets freeze over. What on earth is going on? I got scolded by my supervisors for this. 　 10. Under the weeping plane trees in the rain… It’s been really cold these days. The safety valve pipeline at the outlet of the diaphragm pump here has frozen; the flow rate in the circulating water heat exchanger was set low, and that part has also frozen. Even the pipelines for gasoline and alkali solutions, which hadn’t frozen before, have now developed problems. 　 11. On the Happy First Line Model 43 unit, all heating for the asphalt pipeline is provided by steam jackets; the temperature of the asphalt is 200 degrees Celsius. Yesterday, due to extremely low temperatures, water ended up in the steam system. When this water entered the jacket surrounding the asphalt valve, it was heated by the asphalt, causing the condensed water to vaporize rapidly and expand, which in turn damaged the bottom cover of the jacket surrounding the valve. The bottom part of the valve was thrown more than ten meters away, and the insulation material was deformed. Fortunately, no one was injured. 12. On the Engineering Minor Angerster Model 67 unit, the overflow pipeline of the water seal tank – since the liquid level is always monitored, and the level gauge is designed to function properly with non-freezing liquids – an operational error may have occurred, resulting in both the level gauge and the overflow mechanism freezing up. As a result, the liquid could neither flow out nor in. Thankfully, the tank did not get collapsed or burst. . . . It seems it’s better to preserve everything where there is water. 　 13zhyd121770: The flow of water doesn’t freeze under normal conditions, but this time it did freeze. There are diagrams showing how to repair leaks in the compressor’s cooling water system. 14Xuefeng8678: Sharing an incident of freezing in another device at a facility; in this case, freezing occurred indoors. The current temperature is -25°C, and there is heating in place, so the indoor temperature is around 5°C. Under such conditions, the circulating cooling water should not freeze. A few days ago, it was discovered that one of the pipes had frozen. Upon inspection, it was found that there was a section of the pipe located right at the inlet of the indoor ventilator; due to the cold air flowing there, freezing occurred. As soon as this was discovered, efforts were made to thaw the pipe and restore normal operation. The ventilator in question was turned off, and another one was used instead. Because of the necessary actions taken to deal with the incident, plus the fact that the workshop prohibits the use of mobile phones, there are no pictures available. 15lktch79: When liquid nitrogen turns into gaseous nitrogen, the pipes can freeze. Usually, warm water is used to melt the ice; but a few days ago, the ice formed into a large lump. 　 It’s been really cold this year – 16 degrees in June, with a horizon of 85 degrees Anti-freezing measures in the north have always been the top priority for chemical enterprises during winter each year. This year it’s exceptionally cold; the drain valve used for the piping system is model 20. Yet, even with water flowing through it, it froze up – it really did freeze! It was completely unexpected! ! ! It goes beyond my understanding that water in motion under normal conditions doesn’t freeze! 　 17YJJYZQ91: I never expected that this year, due to the extreme cold weather, even those areas that didn’t have problems in previous years froze up. It’s a serious lesson! The control valve for the gas line (DN250) in the plant froze, and even the connecting pipes froze as well; the plant was on the verge of shutting down. Now insulation has been added to those areas. The liquefied gas lines used in the reforming and cracking processes also froze, so insulation has been installed there as well. The flare lines used for venting gases from coking units and other processes also froze, and insulation has been added to them as well. The lesson here is that we didn’t realize that all types of fluids can freeze – we only considered whether saturated water would form in the fluids depending on the temperature!

18ssln12392: I never expected that the pressure relief valve in the low-temperature liquid nitrogen storage tank would fail because the instrument air pipe (8mm diameter) was too close to the process pipes. The ice formed around those pipes, blocking the instrument air pipe and causing the control valve to lose control. Nitrogen started leaking out slowly. It was deep at night, and I had to climb up to the top of the tank, which is about 10 meters high, with a strong north wind blowing. After identifying the problem, I went down, brought a bucket of hot water, and went back up to melt the ice. Once that was done, the valve worked normally. It was a truly unforgettable experience.

19mifuwen94: The drainage pipes in the plant froze while water was flowing through them, even at temperatures as low as minus 15 or 16 degrees. I used to think that water wouldn’t freeze as long as it kept flowing. Yesterday, we discovered that a dead end in the heating water system caused the carbon steel pipe to crack, even though the pipe was covered with thick insulation and metal sheets. The crack was quite large – for a DN40 pipe, the crack was big enough for three fingers to fit inside, and it was about 10 centimeters long. It’s amazing how destructive freezing can be, capable of cracking pipes with such thick walls! 　 20. No trace left after the wind passed. Last year, the unpurified air system pipelines in our catalytic unit froze, and the air pressure dropped to 0.1 MPa, which was a real concern; we had to use many steam pipelines to heat things up. Later, the addition of filter drying, just like air purification, has performed very well this year! 　 21allen180198198 tells a story from a few years ago, when our factory first started operating: During winter, an emergency occurred, and the boilers were not able to provide adequate heating for the entire factory; it was necessary to prioritize certain areas for heating. However, attention was not paid to the steam traps on the pipe bridges in various areas, and more than half of the steam traps on the pipe bridges in one of the workshops were damaged. This was mainly due to management shortcomings, though it was also related to the experience and skills of the workers at that time. What he wants to convey is that in a chemical plant, good leadership and effective management are key factors determining the success or failure of the enterprise Especially for college graduates entering the industry, an experienced and good leader is far more important than so-called state-owned enterprises and benefits~! 　 22zlx82606681103 I never expected that this year’s cold weather would damage many oil refining and chemical processing equipment. Yet, the members of the community showed great enthusiasm by sharing numerous tips and lessons on how to prevent equipment from being damaged by frost, which has played a very positive role in ensuring better equipment maintenance and uninterrupted production in the future. As a freshman at HaiChuan, I’ve learned a lot of useful things. Thank you for the topic initiated by Chao Ban. 　 23loveli100104 Let me mention another point: for the rich liquid filters used in the catalytic dry gas and liquefied gas purification processes, one unit is in operation while the other is on standby. As we all know, the freezing point of ethylene amine is quite low, around -20 degrees Celsius; therefore, no anti-freezing measures are taken for the ethylene amine system during winter. However, this year it was found during inspections that the large cover of the backup rich liquid filter was bulged. There was a leak at the pad; after removing the large cover, it was found that the liquid inside had frozen! So I’d like to remind everyone: empiricism is not acceptable; when it comes to the pipelines and equipment related to each type of material, they should be treated as if they might freeze. We have a water pump here that is located outdoors, and after using it we forgot to drain the water from it. When we checked it the next morning, the pump casing had cracked due to freezing! We are currently in contact with the manufacturer to replace the pump pit! For outdoor equipment in climates where temperatures drop below 0 degrees, if it is not in use, be sure to drain the water! 　 25wamj6566109 When the cold wave hit, the flow meter for the cooling water of one of our gasification furnace burners froze up, which resulted in no reading of the flow rate. This caused the gasification furnace to shut down, leading to a loss of around 200 tons of methanol – a huge loss indeed! After dealing with the freezing issues and getting things back up and running, more than 100 flow meters, thermometers, and pressure sensors across various sections of the plant were frozen; there were no other consequences or impacts, but it was still very dangerous. Many operations had to be carried out blindly, haha – it’s scary just thinking about it. In previous years, the temperature here dropped to around minus 10 degrees at most, while during extreme cold waves it reached minus 17 degrees. 26 Golden Sunlight 1974110: It’s hard to believe that after repairing the fire hydrants in the facility, the soil used for backfilling blocked the underground leakage valves, preventing the water stored in those hydrants from draining away. When the temperature dropped, the hydrants cracked, and water gushed out in large quantities – a truly spectacular sight. So when repairing and backfilling fire hydrants, be sure to check that there are no leaks left unblocked. In one case, the second return and second control valve of the new hydrogen compressor experienced freezing of its air line; since the control valve was a air-shutting valve, it ended up being fully open, which caused the primary safety valve to activate. Let me share another example – this is based on experience gained over ten years of work, and I hope it can be useful. The heat tracing for the quench oil line in the coking unit consists of one steam injection point and two drain points (one in the pump area and one at 41 meters). The 41-meter-long drain pipeline froze and cracked; subsequent analysis showed that the large flow rate resulting from the open drain in the pump area caused an increase in steam flow, which led to freezing and cracking at the other end. One doesn’t think of such things unless they happen; I hope this is useful to everyone. 29ygtbsb119 – This year has been extremely cold. The pneumatic supply pipeline, at a certain corner, might have frozen inside due to its low horizontal position, which resulted in insufficient pressure in the entire area, causing the pneumatic valves to not function properly. This situation is really unexpected; something like this hasn’t happened in many years. 　 30*nht1127: It’s been extremely cold this year; even concentrated sulfuric acid has frozen. 31*zhongjing008123128: The lubricant in the turbine box of the actuator for our special valves has frozen, which caused the gears to break when trying to open the valve. 32*Xiaoguaiya.129: The C5 pipeline outside has frozen over a length of 5 km – it’s hard to believe. 33*w6948800130: I really never expected this. . . . . Let’s take the opposite example: when unloading ethylene at low temperatures (-104°C), the connection points of the transfer arms freeze up every time. It’s so difficult to remove the oil transfer arm. Who would have thought of using a Russian-style solution? They simply wrapped the connection point of the oil transfer arm with special low-temperature fabric, which served as a temporary insulation measure. After unloading the cargo, the low-temperature fabric was gently removed, and there was no freezing or condensation in the oil transfer arm. 　 34wang*nhua77020133 In the early stages of operation of our company’s facility, there was an ammonia heat exchanger in which water flowed through the tube side while liquid ammonia flowed through the shell side. Due to improper parameter design, when the circulating water stopped, the valve for the gas phase on the shell side was not closed, which resulted in freezing of the tube side of the heat exchanger ； More than 10 tubes froze and cracked; production was halted for a week to address the issue ； Following this incident, our company has reconfigured the interlocks related to the ammonia heat exchanger ； And add relevant exception handling methods to the work standard document ； 　 35 Linlin Shangshang 1.34 million – I never would have thought that water pipes could freeze too! And it created such a long ice column! Seeing my reply, do the sea friends think I’m confused? Hehe, that’s what the production manager at my former company in Taiwan said. That year, the company had just built its factory. After winter set in, a water pump located on the north side of the workshop stopped working. It was strange – it was working fine yesterday, but then it broke today? So a repairman was called. The repairman is a local; he said that the temperature might be extremely low in the shaded areas, and it’s likely that something has frozen there. The production manager found it even more strange: Can pipes really freeze? I watched with great anticipation as the repairman took care of it, and upon seeing the ice column he created, I thought to myself: Pipes really do freeze! Later, I heard him talk about this incident to others on many occasions, exaggerating it every time. Haha, that’s what I heard him say as well. Performance of 36liaifeng137: Deformation of the steam flange gasket at 3.5 Mpa. Solution: Keep the drain valve open to prevent water from accumulating. In Figure 37, there are items such as Kitty-Liu138 fire hoses and fire cannons; these are the ones that people talk about the most in terms of frost protection. We even relieved the pressure from them. But after the cold wave passed, it was these items that were most affected by freezing. 38zuo923139: The drainage pumps at our wastewater treatment station froze a few days ago. The water is drained intermittently, once every four hours for an hour each time. Eventually, the three of us had to use hot water to thaw them out – the hot water available in the tea room wasn’t even enough for that purpose. Later, we asked to empty the water every hour, and there were no more problems; the temperature of the wastewater was around 30 degrees. 　 3968589544141 million – I never would have imagined that for our styrene plant, the light oil slurry is transported to the tank area of the naphthalene plant; the pipelines are around 2000 meters long, with a DN50 diameter. After discovering the poor flow, efforts were made at the styrene plant to find the cause; control valves, flow meters, pumps, and valves were all checked. After several days of investigation, no solution was found, and it was decided to pressurize the entire pipeline as a solution. Later, I inspected the area along the line and found that a section of pipeline leading into the tank area was at the lowest point; I assumed that this pipeline might be blocked. After deciding on a course of action, I sawed open the pipeline, and indeed it was blocked. Cut the pipeline into 5 sections and weld flanges on them for easier cleaning later. Image 4068589544142: I never expected that on the first day of the New Year, there was a leak in the heating line used to supply materials to the facility. An on-site inspection revealed four leaks, all of which were cracks. When questioned on site with the workshop inspectors, it was learned that heating inspections are carried out in each shift; every time, the steam supply valves and traps were found to be hot, while the pipes located too high up in the pipe rack could not be checked. The medium transported through the pipeline is at 60°C, so it should not freeze even if the heat tracing is not in use. After on-site handling, checks were made at the control center against the records, and it was found that the supply of raw materials stopped on the 28th day of the 12th lunar month, with supply resuming on the morning of the first day of the new month. The raw materials froze due to the heating system, causing the pipelines to burst; once supply resumed, the thawing of the materials led to leaks in the pipelines. As a result of this incident, a new regulation was established regarding inspections of the heat tracing lines: it is no longer sufficient to check only two sections, as both ends remain warm due to heat transfer, and any issue with the main line will go unnoticed. It is now required to check one or two points in the middle of the heat tracing lines, with inspections to be carried out once a week (taking into account that it is unsafe to perform such inspections without an access platform in the pipe rack). 　 5 days to vote. As of 3-17-2016, to thank all the sea friends for their active participation. We will select one “most valuable message” and one “most amazing message,” and award them generous prizes (a water bottle or a USB drive). I don’t know which one touched you! If it really helps you, or if you find it very valuable or incredible, please vote for it.