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Something about lubrications

  1. Sep 8, 2009 #1
    Hi guys, i have a question in regards to lubrications inside a pump casing, everyone says it will be bad if water get into the lubricants inside the pump casing. But what exactly will happen if there is water in the lubricant?

    The following is what i think might happen but i am not too sure about them:
    1) the water will kind of 'lessen' the viscosity of the lubricant (even though they don't mix), therefore, the pump cannot operate at full load.
    2) Water and the high temperature within the pump casing will pobably promote corrosions.
    3) Possible cavitation damages, because the heat generated by the shaft might evaporate some of the water inside the casing, thus causing bubble formations.

    Can someone please tell me what exactly will happen if water do manage to get inside the pump casing and to the lubricants? And if it is steam that gets in instead of water, would it causes the same problems or would it actually be worse than having water inside the pump casing?

    Thank you all!
  2. jcsd
  3. Sep 8, 2009 #2


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    We would need more information about the temperature, pressure and other conditions, but if one is referring to bearing lubricant, then it is undesirable to have water getting into the bearings. Water would like cause corrosion, and it could either react with the lubricant and chemically alter the lubricant, or the water could displace the lubricant and allow hard surfaces to wear on each other.

    What kind of pump is this? A pump in a water supply system? A condensate pump? A slurry pump in a process of some kind?

    I used to work on various kinds of water supply and condensate pumps, and the seals were designed to keep water away from the bearings in the casing. Some designs allowed for a little water to leak by the seal, but that water was collected and kept away from the bearings.
  4. Sep 12, 2009 #3
    Sorry for the late reply, and thank you for your reply!
    I posted this as a general question on pump lubricants, just wanted to find what might happen if water gets into the pump casing, but according to your reply, it seems like there will be different problems at different temperature and pressure and also in different pumps.

    Would you mind clarifying that for me please (the general problems in different temp/pressure/type of pumps)?

    Thank you very much!
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