The bevel gear lubricating oil pump is experiencing leakage due to the change from a packing seal to a skeleton oil seal; please help analyze this issue! Thank you
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1. The oil pumps operate in a one-active-one-redundant configuration; after the bevel gear lubrication oil pump was changed from a packing seal to a skeleton oil seal, leakage occurs when it is in the redundant mode； 2. The pump does not leak when it is in operation; however, when one pump is turned on and the other is shut down, the oil seal of the spare pump will suddenly start leaking after two or three days. Please help analyze the reasons; thank you all!
After the first sudden leakage occurred while the pump was in standby mode, the maintenance team installed a frame oil seal of appropriate size, and the pump operated normally without any further leaks. The pump was then stopped and put in standby; two days later, it started leaking again suddenly
The leakage must be due to high pressure.
It must be caused by internal leakage and pressure crossover in the pump’s outlet valve!
The skeleton oil seal can only withstand a limited pressure; it is recommended to use a mechanical seal instead
The skeleton oil seal has a very low pressure resistance; check whether the outlet valve is leaking internally! Is there a check valve on the outlet?
Please pay attention to this sentence in my description of the problem: \"When one pump is turned on and the other is shut down, the oil seal on the frame of the standby pump will suddenly start leaking after two or three days.\" My analysis: When one pump is in operation while another serves as a backup, the backup pump will inevitably experience pressure buildup. Ordinary skeleton oil seals have a very low pressure resistance and can generally only withstand slight positive pressure, which leads to oil leakage. In contrast, the pump that is actually operating does not leak, because when the pump is running, a dynamic oil film is formed at the location of the skeleton oil seal, and this oil film can resist pressure; hence, no leakage occurs when the pump is in operation. Solution: 1) Closing the outlet valve on the backup pump poses a risk. 2) Replace it with a pressure-resistant frame oil seal; one has not been found yet. Brothers, take a look and see if my analysis is correct? Discussion is welcome. :lol:lol:lol
“The pump, when in operation, does not leak, because when it is running, a dynamic oil film is formed at the skeleton oil seal, and this oil film can withstand pressure; therefore, no leakage occurs while the pump is operating. ”I don’t think so about this statement. Centrifugal pumps sometimes experience leakage when in operation but no leakage when stopped, as the sealing chamber is under negative pressure during operation and under positive pressure when stopped.
The selection of the skeleton seal was incorrect. Some skeleton seals are also resistant to temperature and pressure; if the packing is modified, a V-type skeleton seal can be used.