【Weekly Topic】Week 29 of 2011——What should be noted when switching the oil cooler and oil filter in the unit

Reply to 1# gader: 1. Act quickly; when switching the valve, it is necessary to do so swiftly. The two units can be operated in parallel first, and once stability is achieved, one of them can be shut down； 2. As a precaution, it is recommended to increase the oil pressure slightly ； 3. Most importantly, it is essential to fill the backup oil cooler and oil filter with oil to prevent a sudden shortage of oil supply. 4. It is still best to perform the switch when the system is shut down, as no one can guarantee that the switch valve is functioning properly, unless it is absolutely necessary.

During normal operation of the unit, the connection valve between the standby oil cooler and the oil filter remains fully open (this valve must be closed during maintenance). This ensures that both the standby oil cooler and the oil filter are always filled with oil, thereby preventing fluctuations in oil pressure that could cause the unit to shut down during an online switchover； To perform an online switchover, first check whether the backup oil cooler and oil filter are filled with oil. Open the valves at the top of the backup oil cooler and oil filter that connect to the oil tank, and use the oil return sight glass to verify whether oil is flowing back into the tank. Once oil starts flowing back into the tank, close these valves; this indicates that the backup oil cooler and oil filter are fully filled with oil. When the unit is running and an online switchover is carried out, this will prevent fluctuations in oil pressure that could cause the unit to shut down ； Remember: Before performing an online switch, be sure to check everything thoroughly and confirm before carrying out the switch operation ；

Everything said upstairs is correct; I’ll add my own method to it. I’ve always done it this way, and I won’t change the way of throwing bricks. Disengage the hydraulic interlock; it’s fine if the oil pressure drops momentarily, as this causes less damage to the machine than stopping it under load. However, no fluctuations in oil pressure have occurred even after making the switch numerous times – simple operations like these shouldn’t cause any problems; the key is to ensure the tank is full of oil, and then nothing will go wrong regardless of how the switch is used.

What was said about the 2nd and 3rd floors is very good. To add something, another advantage of having a warm standby system is that it prevents excessive temperature changes during switching. On one hand, too low a temperature is harmful to the bearings; more importantly, it can lead to a large pressure difference, which in turn causes fluctuations in oil pressure

For this, you need to draw on experience in pump switching. First, check the interlocks; the other unit should be in standby mode, and the pipelines must be filled with oil. The standby unit should be opened slowly, while the active unit should be closed slowly. Close coordination is required between the field operations and DCS control, with attention paid to pressure changes, especially in those units that are sensitive to interlock values and equipment that requires oil. The switching procedure for commonly used dual filters is as follows: 1. Slowly turn the valve handle in the opposite direction; tapping the handle manually during the switching process allows for fine adjustments. The purpose is that when opening the handle on the other side, by referring to the pressure after the oil filter, if a slight drop in oil pressure is detected, adjustments should be stopped immediately. After some time, the oil pressure returns to its normal level, indicating that all the gas inside the filter cartridge has been expelled. While ensuring that the pressure does not drop, the plug is gradually turned in the other direction to complete the cutting process. 2. For the removed filter cartridge, the drain valve inside the tank should be opened promptly, as well as the exhaust valve at the top of the filter cartridge, in order to drain all the oil from it. Remove the filter cartridge, clean/replace the filter element, fill the cartridge with lubricant of the same type until it is full, then reinstall it. 3. Use the first method to switch. A small amount of air (at the filter cartridge seal) can be slowly released into the oil, and after switching over, the exhaust valve can also be slightly opened (using a rag to prevent splashing); this will not affect anything else. Note: The exhaust/oil filling method, if not used properly, can easily lead to vehicle shutdown accidents.

1) Open the connection valve between the oil filters； (2) Open the exhaust vent of the backup filter to release air ； (3) Rotate the switch handle to the proper position ； (4) Check the pressure difference, etc.; the oil cooler and oil filter of this unit can be used in alternation. However, special attention is required during the switch-over, as improper operation can cause oil pressure fluctuations and lead to the machine shutting down. Vent the air before switching, and act quickly during the switch. To ensure a smooth switch, it is required that the three-way ball valve section remain flexible. It is best to conduct the switching test while the system is stopped, in order to verify whether the flexibility and speed of action required during the switching process can be met; otherwise, it is not advisable to perform the switching while the system is running, but rather during a shutdown. To ensure the safe operation of the equipment, switching operations must be carried out strictly in accordance with the procedures. First, fill with oil and vent the air, then perform the switching operation.

Reply to 5# 1dream: Preparation involves keeping the connection valve between the online filter/oil cooler and the backup filter/oil cooler fully open, so that the backup oil cooler and oil filter are always filled with oil. In my opinion, the exhaust valve of the backup filter/oil cooler can also be kept open; this helps to maintain a full level of oil, no air in the system, and an appropriate temperature in the backup filter/oil cooler, thereby preventing significant fluctuations in oil pressure and temperature in case of an emergency switchover

Switch over slowly, and make sure the backup device is filled with lubricant before making the switch to avoid significant pressure fluctuations.

When switching, make sure to equalize the voltage and exhaust first.

When switching over, it’s important to make sure that the backup unit is fully filled with oil – don’t rush. I once switched over in a hurry and did so before the oil level in the backup unit was full; if the interlocks hadn’t functioned, it would have caused the unit to stop operating. During online maintenance, the spare unit can be filled immediately after the maintenance to save time on filling oil during switching.