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differential bypass difficulty

norfitz Member Posts: 54
I'm having difficulty comprehending Honeywell D146M differential pressure bypass valves, let alone explaining how to set them up. The instructions are not helpful. There's a dial with arrows indicating more or less what? Pressure? Or Flow? Does the view window tell you anything helpful at all?

I understand that I should be setting them for a higher pressure than that of the system so that it will open when flow is reduced to an undesirable level by zone valves, but the actual setup and observation of the valve is confusing.

Caleffi's DPR's are easier as they have a "head" scale which I can compare to a known pump curve.

Can anyone enlighten me, please?


  • Paul Pollets
    Paul Pollets Member Posts: 3,656
    Better instructions

    You should contact Honeywell tech services or your local rep for better instructions.  The Oventrop unit comes with a pump comparison chart to set the device.   
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