I have a colleague (old school) at work who insists on the use of PICCV for a computer room air conditioner as basis of design. The Lieberts (our preferred vendor) come with either 2- or 3-way valves internal. We prefer 2-way for our datacenter. Either way, my partner insists in taking out the valve that comes with the Lieberts, only to replace them with externally controlled PICCV (Belimo). GPM is about 100 per Liebert. He claims, if we don't do this we would need a circuit setter per Air Handler.... The algorithms for controls (for valve modulation) that Liebert has have worked perfectly in other datacenters I've worked in.Pressure-independent control valves work on systems that have variable flow conditions, e.g. variable loads in chilled water HVAC piping, and especially time-variable loads in multi-branch piping system. You'd think a data center would have fairly constant loads, but I can imagine servers with various power saving schemes (sleep modes for drives, cpu's) that could have heat output varying over time. Probably not as strongly as in more heavily human-occupied spaces, but there should be some variation just with daily weather variations creating heat loads on the building walls.Agree with gerhardl, 3-way mixing valves are a really dumb idea - you throw away a lot of energy when the 3-way valves dumps and mixes out chilled water.I'd look for a valve that has the capacity you need, not picking one from the top of its rated flow range with no capacity above that rating. There are other, better pressure independent valves out there - google is your friend.

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