Why does the mechanical seal leak sometimes and not at other times during operation?
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The mechanical seal leaks at times during operation, but not all the time; there are no issues with the shaft’s play or circular runout. What other reasons could cause such a problem?
Check whether the flow rate of the medium at the pump inlet is stable, and whether the outlet pressure gauge fluctuates. I think it is mainly due to fluctuations in the medium properties, which cause intermittent leakage, as well as possible issues with the expansion and contraction of the mechanical seal spring.
One of our liquefied gas pumps had a sealing issue where it would leak at times and then stop leaking again; the maintenance team said that mechanical impurities sometimes got into the seal, causing the problem. The seal was recently repaired, and since then the issue has been resolved.
It can be modified into a pump-mounted series dry gas seal, along with an auxiliary system. Guaranteed leak-free operation
Is there any jamming in the axial movement of the compensating element’s push ring or spring?
The cost of making this change is too high for me. I’m using a pump with minimal costs, designed for pumping slurry; currently, it’s equipped with a modular mechanical seal that uses small springs
First, check whether there are any issues with the flow rates at the pump’s inlet and outlet, as well as with vibration. Next, the mechanical seal can be disassembled to determine whether the rotating ring is stuck in the spring seat (pay attention to looking for any obvious scratches on the outer diameter side of the rotating ring). From what you’ve described, it seems very likely that the rotating ring is stuck
Generally, it’s due to poor dynamic ring compensation; cleaning and replacing the O-ring are required
First, check for external factors: whether the pump medium and various process parameters are normal. If there are no issues, then it’s a problem with the seal itself – issues with the spring, or damage to the sealing ring or sealing surface, which requires disassembly and inspection