Problems with the sealant?
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Problems with the sealant? Our facility uses shielded pumps, and the sealing fluid for these pumps is ethylene glycol. However, I heard that it isn’t pure ethylene glycol; instead, it’s a mixture of ethylene glycol and some water. What is the ratio of these components? Why isn’t pure ethylene glycol used as the sealing fluid?
The ratio of water to ethylene glycol is generally 4:1. The amount of ethylene glycol used alone is not large, so the cost doesn’t increase much; however, ethylene glycol is volatile, which is why it needs to be used in combination with other substances.
Considering heat capacity and cost, water and ethylene glycol need to be used in combination.
The shielded pump you are referring to is likely a cryopump; the purpose of adding water is mainly to lower the freezing point of ethylene glycol