The valve fails to operate for an extended period of time and gets stuck
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I work in the production of styrene at a chemical plant. Our company’s styrene production facility has an annual capacity of 320,000 tons of styrene; it consumes 89,552 tons of ethylene per year and 249,720 tons of benzene per year, with an annual operating time of 8,000 hours. The styrene unit utilizes technology imported from the American company Stone & Webster (SW), while the ethylbenzene unit employs Exxon Mobil’s EBMax liquid-phase alkylation technology for the production of ethylbenzene; the styrene unit also uses TOTAL/BAGER’s adiabatic dehydrogenation technology. The scope of this import includes both the process packages and the basic design. The styrene plant is located to the southeast of the VCM plant in the company’s northern factory complex, between Xinpu Road 3 and Road 7 within the factory area; its east side is close to the factory’s perimeter wall. The intermediate tank area is located on the south side of the facility, in the plot to the south of Xinpu Third Road; to the east of the intermediate tank area lies the existing LNG storage and gasification station. The styrene plant includes an ethylbenzene unit, an ethylbenzene dehydrogenation unit, a styrene distillation unit, intermediate tank areas, a utility distribution system as well as substation areas, control rooms, and a flare unit. The control room, substation, and flare unit are located outside the plant boundary. The power transformation and distribution station of this facility is located to the east of the VCM substation ； The torch unit is located in the northeast corner of the North Plant area of Xinpu Company. The utilities such as water, electricity, and steam required by the facility are all supplied from utility facilities. The ethylbenzene unit operates under high pressure, with a reaction pressure of around 4.0 Mpa. The manual valves at the inlet and outlet of the ethylene processor, as well as the manual valve for the seven-stream ethylene feed, are very difficult to operate; we need additional rods to operate them, and three people are required to do so simultaneously. Moreover, each valve can only be opened by about 30 degrees. Do any of you have any ideas on how to address this issue of difficult valve operation? Remarks: 1. Our company is adjacent to a phosphate fertilizer factory; there is a lot of dust in the area, which causes severe dust accumulation on the valves ； 2. The valve does not operate for an extended period of time ；
I’m not sure what valve you’re using or what its diameter is. For medium and large diameter valves, if the drive type is manual, the torque required is quite high; next time it’s time to replace the valve, you can opt for a mechanical drive system such as one based on turbines, spur gears, or bevel gears. If you have the money, there are electric, pneumatic, and so on. A large pressure difference before and after a valve can also increase torque
Our company has specifically developed special butterfly valves to address issues such as dust accumulation and jamming in butterfly valves used in the gas industry. I’m not sure what kind of valves your company deals in.
If the valve has difficulty opening and closing due to dust accumulation and prolonged inactivity, it is recommended to first clean the valve’s lifting screw, apply lubricant to it, and then cover the exposed parts of the screw with oil-paper or similar material.
Our company uses 4-12 inch gate valves, and indeed there is a problem of high pressure on both sides of the valves! We have also tried applying butter to the valve stem or injecting lubricant into the valve core, but if it isn’t used for a long time, dust will accumulate over time even with lubricant present, causing jamming! Therefore, our company has also established a valve maintenance team dedicated to carrying out maintenance and lubrication work on valves, but the results have not been significant!
Previously, the outlet gate valve of our company’s pumps wouldn’t open; the reason was that the copper sleeve was stuck. After it was replaced, the valve was able to open again
If there is no jamming in areas such as the valve stem. It is recommended to switch to a flat gate valve, as it is very easy to operate. If you don’t want to replace the valve. So only the actuator needs to be added. Things like spur gears. You can go for one with a lighter switch.
Common problems~Lack of regular use leads to issues such as sticking components, rusted valve stem threads, and rusted valve cores and bodies. Only through regular maintenance and operation can the effort required to open and close the valve be reduced
Ball valves are used, resulting in a low probability of rusting