mechanical seal
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Our company's low-temperature methanol washing chemical process pump uses an imported pump produced by United Pump Industry Company of the United States. This pump uses a series cartridge mechanical seal. In actual production, the mechanical seal (especially the inner seal (especially the inner seal (shown as the PLAN52 sealing tank liquid level is full)) often breaks down. About February,* * It has increased our costs and production stability. Have you ever encountered this situation and how did you solve it? By the way, our operation and maintenance are normal. The mechanical seal manufacturer is FLOWSERVE.
In order to improve the stability of production, you can get a backup pump for the pump you mentioned. I don’t know the judgment I made based on the centrifugal pump. I hope it will be helpful to you. It is estimated that your sealing water pressure will sometimes be lower than the pressure of the pump, causing friction between the dynamic sealing surface and the static sealing surface. With wear and tear, your problem will naturally occur.
PLAN52 provides buffer fluid from an external container to the external seal of the pressureless double-end seal. During normal operation, the circulating fluid is maintained through an internal pumping ring. The container usually continuously vents to the vapor recovery system and maintains a pressure lower than the seal chamber pressure. I don’t know if the sealing buffer system of the LZ pump is configured according to the requirements of PLAN52. From what LZ described, if the sealing tank is full of liquid, it is certain that the mechanical seal is leaking. The full liquid may also be caused by internal leakage of the replenishing valve (normally closed). I don’t know if it has been checked and confirmed. Since FLOWSERVE is a well-known brand, there may be another reason why the machine was damaged after only two months of use. Therefore, it is recommended to first determine whether PLAN52 is appropriate and whether it can be changed to PLAN53. ； If it is true that PLAN52 is enough, but the mechanical seal is often damaged and leaking, it may not meet the relevant requirements of PLAN52. It is recommended to add a flow indicator and a pressure gauge (if the requirements are not mentioned when matching, it will not be equipped), etc., which will facilitate daily maintenance.
For the series seal you are using, whether there is sealing liquid between the seals, whether the sealing liquid pressure is appropriate, and whether the sealing liquid medium is appropriately selected. Please check it out.
Check whether the sealing liquid circulates smoothly, because it plays a lubrication and cooling role. If the sealing liquid does not flow, the temperature between the seals will be high and the seal will be easily damaged.
Thank you for your help. This pump PLAN11 is flushable with an inner seal, and PLAN52 is flushed with an outer seal. The sealed tank is filled with a bucket, so there is no valve leakage. This mechanical seal has an impeller, which can forcefully circulate the lubricant in the sealed tank, and there is circulating water in the tank for cooling. Let me ask again, what is the maximum temperature that this kind of seal can generally withstand?
I have little talent and knowledge, so I would like to express my opinion. PLan52 is an unpressurized liquid storage pipe. If the liquid storage pipe is full, it means that the inner seal of the series mechanical seal is leaking. In view of the reasons mentioned above, I would like to add one more thing. It may be that the sealing liquid is selected incorrectly and corrodes the seal of the mechanical seal. May I ask what sealing fluid the host uses for sealing? White oil or what?
The poster uses a series container mechanical seal. In actual production, the liquid level of the PLAN52 sealing tank is full, indicating that there is a problem with the inner seal, which has nothing to do with the outer seal. Since the inner seal flushing fluid is provided by the medium in the pump, the poster please carefully check the temperature of the seal oil entering the seal cavity, which is generally controlled at around 80 degrees. Please check the effect of the internal sealed oil cooler. I think the key to the problem is here.
PLAN52 is used for tandem mechanical seals, while PLAN53 is used for double mechanical seals, which must be back-to-back. If this situation occurs in your company, it may be because there are too many impurities in the medium. It is recommended that PLAN11 be replaced by PLAN31
It is said that the pressure of PLAN53 is at least 1-2 bar greater than the pressure of the shaft seal chamber, but how to determine the pressure of the shaft seal chamber? I currently have a high-speed pump with a lift of 560m and a medium density of 0.89. The pressure at the center of the impeller cannot be determined. Let’s calculate it as 50bar. However, the maximum value of the pressure gauge on the buffer tank is only 21bar. Please give me some advice. Thank you very much.
This post was last edited by QHDKD on 2008-2-23 01:07 ]