Pump sealing, lubrication, cooling, flushing
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I have a question: there is a small oil container on the side of the pump, which is used for lubrication. Then, there is usually an oil tank on the pump as well, something that looks like a small heat exchanger; is that container also filled with oil, and does it serve a sealing purpose? Is it for flushing machine seals? Why use oil? What are the differences and connections between seal flushing and the cooling circulating water on the pump? Can flushing the mechanical seal also be used to reduce temperature? Also, how should one choose the flushing plan? What is the difference between Plan 21 and Plan 22? Why not draw the flushing fluid from the pump outlet instead? I hope those of you who are familiar with this can give some guidance. Isn’t this related to equipment technology? All these things are quite confusing···
1. The small oil reservoir on one side of the pump bearing housing is called a constant-level oil cup; it is used to automatically supply oil to the bearing housing in order to maintain an appropriate oil level, based on the principle of a communicating vessel. 2. The storage tank located next to the pump is used in sealing systems that adhere to the PLAN52\53A standards specified in API682; it is employed for double-face sealing. It generally contains white oil of grades 5–15, but it may also be ethanol or an ethylene glycol aqueous solution, depending on the nature of the medium being handled. 3. The cooling water from the pump is sometimes directed to the bearing housing in order to cool the lubricating oil and thus ensure the lifespan of the bearings. 4. The difference between 21 and 22 is that the 22 model comes equipped with a filter. Due to the risk of clogging of this filter, it is generally not recommended to use the 22 model. If its use is necessary, it is advisable to use two filters in parallel, installing valves before and after each filter so as to switch between them during use and to clean the filters regularly.
It is recommended to first read books related to mechanical seals. The oil cup is used to supply lubricating oil to the pump bearings, while the mechanical seal system prevents the leakage of the medium inside the pump; they are two separate systems. The mechanical seal flushing scheme is used to provide lubrication and cooling to the sealing surface as well as to remove impurities, thereby creating a favorable environment for relative movement of the sealing surface and extending its service life. Primarily, a pumping medium is directed to the sealing surface through pipes, creating a small circulating flow. For flushing procedures, it is recommended to refer to the API682 standard.
1. Sealing ring flushing involves cooling and cleaning the sealing ring; it uses both a flushing fluid and an isolation fluid. The flushing fluid can be the medium itself or an external medium, and it can be mixed with the pumping medium, as in Scheme 32； According to the operational requirements, when the flushing medium must not contaminate the pumped medium, a double-end mechanical seal is considered, with an independent isolation fluid being used, as in Option 53. 2. As described in 1 for the mechanical seal cooling water, the pump cooling water can be tap water, which is used to cool the pump body itself and the bearing areas, etc ； It is best not to use the pump’s cooling water to directly wash the mechanical seal; firstly, this is because the cooling water pipes in the pump are usually made of carbon steel, and secondly, the cooling water itself is not clean. 3. The flushing scheme can be selected based on the properties of the medium and the information provided by the machine seal manufacturer. The main difference between schemes 21 and 23 lies in the source of pressure for the flushing fluid: scheme 21 uses the pressure at the pump outlet as the source of pressure, but this approach results in greater load on the heat exchanger and an increased tendency to scaling. Scheme 23 relies on the pressure from the pumping ring to supply the flushing fluid, offering higher efficiency compared to scheme 21. 4. Finally, going back to earlier – what is that oil tank on that pump? I’ve never seen it before: L
2L explains it very clearly; you can learn from it as well
The oil cup in the bearing housing is used to top up oil for the bearing housing, while the fluid used for mechanical seals seems to be in a sealing fluid tank. Double-end face mechanical seals are widely used, and different sealing fluids are employed depending on the type of medium. The flushing scheme for mechanical seals is relatively complex; it’s best to look for relevant information on Baidu and study it carefully, as the differences between various mechanical seals and media all affect the choice of flushing scheme.
Does it involve a specific flushing structure for sealing?
Judging from the description, it seems to be the flushing method for PL53A, where circulating water is used to cool the sealant, which in turn serves to cool and remove impurities from the mechanical seal.
It would be better for the manufacturer to decide on this shaft seal flushing and cooling scheme; it’s not easy to make a choice just by looking at technical specifications and such. Also, are most seals these days not using a single surface anymore? Have they all been changed to double-sided?
It mainly depends on the properties of the medium; dangerous and flammable media usually require double-ended types. If it is for transporting clean water, there is no need to use double-end faces. 1CW will work
Isn’t that jar above the white oil jar?