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Multistage pump overheating needing new seals

Multistage pump overheating needing new seals

Multistage pump overheating needing new seals

(OP)
We have a 39 story high rise building that has a booster pump in the basement that sends water to the cooling towers on the roof.  The discharge temperature of the water is excessively high 170 f.  The seals have been replaced the engineer who designed it says the booster pump is sized properly.

apart from dead heading why would the discharge temp be 170 when the suction temp is only 50 f.

the seals should be rated for this service.

does any one have any experience in this or suggestions.

RE: Multistage pump overheating needing new seals

Its not a seal problem.  If the pump is sized properly, then you are not properly running it.  It is running with no or too low of a flow.  What is the pump's rated BEP flowrate, BEP efficiency and BEP head for your pump?  What flowrate and head are you running at?

BigInchworm-born in the trenches.
http://virtualpipeline.spaces.msn.com

RE: Multistage pump overheating needing new seals

Mr Inch is correct.  You are most likely running at low or no flow.  But the design of the system may be the root problem.  

If the flow is going to a cooling tower on the roof, I assume it is also returning down to the level where the pump is located.  We have a few similar installations where a booster pump was needed to boost the flow up a structure.  The sizing of the pump needs to be evaluated for this unique condition.  Did the designer try to take credit for the full head gain by the fluid flowing back down from the top?  Unless you have a restriction on the return leg that keeps enough back pressure so you don't draw a hard vacuum at the top, then you cannot take credit for the full head gain on the return side.  A vacuum can only support 32 feet of water.  Even if the system is properly designed for normal conditions, did they allow for the transient conditions needed to establish flow?  Until the system is flooded, there is no head gain on the return side.  The pump needs to be able to boost the flow up the structure to flood the lines initially.  Once return flow is established, depending on the particulars of the system, you may be recovering some of that head on the down flow leg.  These are the sorts of questions I would be asking if I were you.

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