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piping question, tight tees

Dave2012Dave2012 Member Posts: 1
Hello, i know the correct practice of using closely spaced tees to some off a primary loop is to keep them approx 4 pipe diameters apart, my question is that if they are installed 6-7 pipe diameters apart, what potential problems could this cause? This is on mod/con boiler supplying 1 heating zone, piped as primary secondary.


  • Tim_HodgsonTim_Hodgson Member Posts: 59
    No problems

    for a one zone system... and if you decide to add a second zone then add a flow check valve to the first zone.

    Good luck,

  • icesailoricesailor Member Posts: 7,265
    Closely Spaced Tees:

    Everything I have read about closely spaced tees call for 4 to six pipe diameters between tees. There is also a distance the tees are supposed to be from a change of flow direction, like an elbow.

    Mixing of the primary and secondary water is supposed to take place in the tees. The closer the tees, the better the mixing. The farther apart, the worse the mixing. The farther apart, it becomes, not mixing but something else. The closely spaced tees cause a mini=circuit through the primary loop.

    I've never seen 7+ pipe diameters recommended as closely spaced tees. Read the manufacturers installation instruction for their definition of "closely spaced tees". If you feel that the manufacturers suggest 7 or more pipe diameters for closely spaced, then it is a proper spacing. If not, one could say it is an improper spacing of the tees.

    In my opinion.

    Why is there a question?

    That's the nice thing about Hydraulic Separators. You can't screw them up.
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