Unit shutdown

The heavy oil in the distillation system must be purged; subsequent units such as stabilizers do not require the flow of oil to be stopped. If the units need to address certain issues, it is essential to follow the procedures strictly and install blind flanges as necessary

I mean, could it cause problems such as corrosion?

Hehe, corrosion will definitely occur. It’s something that cannot be avoided even when the device is operating normally. The absorption and stabilization section can operate in a three-column cycle to promote flow, thereby reducing corrosion in specific areas of the column equipment.

Corrosion is bound to occur; once the heavy oil is removed, it won’t be a big problem

Regarding corrosion, it is better for the pipeline to have oil in it than to be stored after it has been cleaned. Diesel can protect the heating furnace tubes, while gasoline can be circulated regularly.

After parking for such a long time, it’s best to sweep the lines for safety. Whether corrosion occurs depends on the concentration of harmful ions in the water. However, parking can easily cause the operators to let their guard down, potentially leading to safety accidents.

Whenever the plant is shut down, it will definitely cause corrosion of the equipment; heavy oil (fractionation) is particularly important! Handle it properly, it’s no big issue! ! Pay attention to the application of auxiliary systems! ! ! :handshake

Problems may arise with the light oil system; the heat exchangers can corrode. This is especially true regarding liquefied gas, as the water coolers contain high levels of sulfur. If liquefied gas leaks in, it will cause problems with the circulating water

For long-term parking in large areas, it is best to sweep the lines for safety reasons. But since the heavy oil line has been cleaned, it’s okay to not remove the light oil for now.

For long-term parking, it is best to sweep the lines for safety reasons. However, for devices such as stabilizers, oil cleaning and wiring inspection can also be postponed temporarily.

Water systems can corrode the tube bundles

The key is the heavy oil; failing to clean the lines is a serious problem, and it’s important for the next startup.:handshake

Corrosion is inevitable; once the heavy oil is removed, corrosion should not be too severe. However, it is necessary to pay attention to the operation of the auxiliary systems and conduct regular inspections.

First, determine whether there is a long-term shutdown or if there are any maintenance tasks in the short term. If so, it is generally required that the corresponding pipelines be thoroughly purged. However, even with just a shutdown and no maintenance work required, some of the pipelines can still be purged, while others can be lightly pressurized for displacement. Mainly, the heavy oil pipelines must be replaced with light oil or purged thoroughly, while the light oil pipelines do not require any treatment. If there is oil in the pipeline, will it cause corrosion? There’s no need to worry about this issue. The pipeline is filled with light oil, so there should be no problems. But be careful: if it is winter, after purging the pipelines, pay attention to preventing freezing and condensation! Remember! ! !

For sulfides, they do not decompose at temperatures below 120 degrees Celsius, and there is virtually no corrosion when they are anhydrous. At temperatures between 120 and 240 degrees Celsius, the activity of sulfides is very low, so corrosion is essentially absent. Naphthenic acids generally do not cause corrosion at 220 degrees Celsius. H+ corrosion occurs only when the temperature is above 220°C and the pressure is above 1.4 MPa; Cl- corrosion can still occur even when the system is shut down, unless its concentration is extremely low. Hydrocyanic acid and other forms of stress corrosion are unlikely to be a concern under conditions of shutdown. Alkalis can cause \"alkaline attack\" on carbon steel, but this also depends on temperature and concentration. If the system is left shut down without maintenance, it is necessary to consider the specific circumstances.