The mechanical seal of the boiler circulation water pump has a short service life
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RT, I hope the experts on this forum can help address the issue of the short service life of the mechanical seal on this pump. The pump in question is a hot water pump produced by Chengdu Yitong Pump Co., Ltd.; it belongs to the centrifugal pump category. The inlet pressure of this pump is 3.6 Mpa, the temperature of the fluid is around 260°C, and the fluid itself is deionized water. During recent inspections, white deposits were found on the impeller, as well as a small amount of such deposits inside the stationary and rotating rings of the mechanical seal. This pump uses a single-piece mechanical seal, and leakage was rare just 2 years ago; I’m not sure what’s causing the leakage issues this year – the seal starts leaking after only 2-3 months of use. Upon disassembly, wear was observed on the stationary and rotating rings :( Please help me out, experts on the forum :( If there are problems with the water quality, what tests need to be conducted? Thank you very much
Main tests: machine impurities; COD is likely due to water issues
I have tried using vibration isolation rings from other manufacturers, but it still doesn’t work and their lifespan is even shorter
I asked the manufacturer; what did they say?
The wear of the rotating and stationary rings in mechanical seals is mainly caused by high medium temperatures, which prevent the formation of a liquid film and lead to dry friction in the seal; or by excessively high specific pressures, which result in the breakdown of the liquid film
The medium temperature is too high, leading to easy vaporization; a double-end face seal can be used to improve the sealing conditions, and better materials for the friction pairs can also be employed.
Change to a double-end face mechanical seal with flushing
With such high temperatures, it is necessary to check whether the seal flushing and cooling water are functioning properly.
You can also check the axial play