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Makeup pump for tower.

Makeup pump for tower.

Makeup pump for tower.

Dear all,

Please help me to understand about the makeup pump design.

Open head of chilled water pump as follows:-

Discharge- 700kpa

Suction -420kpa

Head of pump - 292 kpa

What pressure I can set the makeup pump for cut off.

Whether delta of discharge or suction or suction pressure.

Please help me to solve this .



RE: Makeup pump for tower.

If I understand the question correctly you are asking what pressure you need to set a make-up water pump for maintaining water volume in a chilled water system.

Where in the system does the make-up pump connect? The pump must generate enough pressure to push water into the system at the location of connection - you need to figure out what the pressure is at this location.
If the make-up is connected immediately before the pump, it needs a set point of 420 kPa.
If the make-up is connected immediately after the pump, it needs a set point of 700 kPa.
Any other point will require a set point somewhere in-between.

I've always found it best to provide make-up at the point of system pressure/expansion control (the expansion tank). This is the point where the system pressure is set, therefore it is the one point you "know" precisely. You can get combined expansion tank/pressurization/make-up units which make all this very simple.

Note, one of your readings is wrong*, head of pump = discharge - suction (700-420 = 280)
* unless your suction and discharge points are measured before/after other components (strainers, valves etc)

hope this helps.

RE: Makeup pump for tower.

just noted the subject referred to a tower. is this an open or closed tower?
if open there will be no expansion tank obviously.

all other comments still stand

RE: Makeup pump for tower.

I don't understand the question.

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