What are the reasons for the drop in liquid level in the buffer tank of PLAN52 mechanical seals?
Thread Content
A API 682 mechanical seal system is in use; during operation, the liquid level in the seal tank drops (the pressure is lower than that of the medium). No external leakage was detected upon on-site inspection, and the cause of the drop in liquid level remains unclear Could the experts here please analyze it?
If there is no external leakage, then it must be an internal leakage; one possible reason is that the sealing chamber is under negative pressure.
It’s likely a seal leak on the medium side; the buffer has leaked into the pump chamber. The vehicle should be stopped as soon as possible to check for the cause of the leak
The P52 system operates without pressure, so the pumped liquid will leak to the subsequent seal of P52, causing the pressure inside the P52 siphon tank to rise; this triggers an alarm. If the subsequent seal of P52 also fails, the liquid will leak outward along the shaft sleeve or shaft. If it is confirmed that there is no leakage, then it should be checked whether the pressure continues to drop. If not, it is necessary to examine whether there is a leakage in the internal coils or if the coils are blocked, with liquid leaking into them
This post was last edited by backcat666 on 2018-7-22 at 16:42. Have you figured it out? Is it PLAN52 or PLAN53? The isolation fluid pressure for PLAN52 is lower than the medium pressure but not lower than atmospheric pressure； If the liquid level in the isolation tank drops, it is likely that there is a leak in the mechanical seal on the outside side, i.e., the side exposed to the atmosphere. Check carefully for any leaks; sometimes the leakage is very minor ； What is the pressure in the isolation fluid tank? If the pressure in the isolation fluid tank is higher than that of the cooling water, it is possible for the fluid to enter the cooling water pipeline due to damage to the cooling water pipes; however, this is not possible if the pressure in the isolation fluid tank is lower than that of the cooling water. Leakage in the mechanical seal on the medium side can only cause the level of the isolation fluid tank to rise ； In the case of plan53, leakage from the mechanical seal on the medium side will cause the liquid level in the isolation tank to drop.
This post was last edited by backcat666 on 2018-7-22 at 16:44. Have you figured it out yet – is it PLAN52 or PLAN53?
As mentioned above, it’s highly likely that with PLAN53 52, information can only leak out
1. If light hydrocarbons volatilize in small amounts, they may carry away some of the seal oil; especially at the moment when the equipment is restarted after being shut down, leaks can occur frequently. Usually, the situation improves after it has been operating for some time. 2. Check whether the check valve from the on-site seal oil tank to the seal oil reservoir is not functioning properly, which could cause the oil to flow back, as the liquid level in the seal oil reservoir is generally higher. 3. It is also possible to check the circulating water in the seal oil reservoir, but this is less likely to be the cause