Chilled Water System

[rhsears]

Would these type valves function properly on a closed-loop system?

Looking at installing a VFD configuration on the recirculation pumps in a chilled water system in one of our facilities.

In our current configuration we have two, single-speed pumps.  One on-line while the other is in standby.  We have two chillers.  We use both chillers in the summer and one in the winter due to differing loads.  One of our pumps has a 500 gpm capacity, and the other is a 196 gpm pump.  The 500 gpm pump is used when flowing through both chillers during summer operation.  The 196 gpm pump is used when flowing through one during the winter.

We would like to replace the 196 gpm pump with a pump equivalent to the 500 gpm pump.  This would offer redundancy during summer operation.  During winter we need to reduce the flow rate (gpm) because the 500 gpm pump would erode our evaporator tubes when flowing through one chiller.

Would your valve help in this case?

[Cary Austin]

A CSV works well with chiller applications.  It will maintain a constant pressure to the chiller from as little as 5 GPM to as much as the pump will produce (500 GPM).  The CSV will not do the differential pressure thing like you can do with a VFD, but that is rarely necessary.  The CSV will vary the flow by maintaining constant pressure.  If you open up more demand, the CSV will supply more water.  When you demand less water, the CSV will deliver less water.  The CSV will match whatever flow rate is demanded.