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Circulator Sizing - Help

GeorgeHC Member Posts: 1
edited January 2015 in Radiant Heating
Will a B&G 2" circulator work properly and efficiently if installed on a one-pipe Monoflo diverter-tee system that has 1.25" main piping? The pump flanges and volute openings are 2", so I would be using a couple of reducers on the flanges to get this down to 1.25"

According to the pump curve, this pump is ideal for the required flow rate (10gpm) and head (10ft) that I have in this system. I'm just wondering if the reducers will create too much resistance and heat when the pump is running. This pump is brand new and free, so that's the only reason I am considering installing it. The current pump has a 1.5" volute and flanges, but is failing (motor and seal bearing assembly).



  • Gordy
    Gordy Member Posts: 9,514
    Yes, you should be able to get the appropriate flanges for it. What's the circ model?
  • Steamhead
    Steamhead Member Posts: 15,331
    That pump is way too big. It will cause a lot of rushing water noise in the system and use way more electricity.

    Sell it on eBay and use something like a Taco 0010.
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
  • SWEI
    SWEI Member Posts: 7,356
    edited January 2015
    Frank obviously knows what some here may not - that 2" is a model number for a specific three piece B & G circulator pump. It's a 1/6 HP three piece design with a curve that does indeed flow 10 GPM at 10 feet of head. That point lies at the left end of the curve. The other end is nearly 70 GPM at zero head.

    The 008 curve gets very close to that point. The VT2218 nails it.