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piping choices

Larry (from OSHA)
Larry (from OSHA) Member Posts: 728
in THE MAIN WALL
I'm wondering if check valves are needed on the supply side of the baseboard circuit if I put the zone valves on the return. This diagram is the basic plan with the exception of the zone valves on the return to hopefully reduce the tendency for them to bang when closing with more than one zone still calling. (yes installed in the right direction)

Any thoughts are appreciated.

Larry

Comments

  • ernie_3
    ernie_3 Member Posts: 191
    No

    The zone valve will provide positive shut off and no gravity circulation can take place. Save the money on the check valves, they are not needed in this application.
  • Weezbo
    Weezbo Member Posts: 6,232
    the check is a waste .

  • dconnors
    dconnors Member Posts: 215


    Zones valves slam for a reason. Some close with the flow and are more suseptible to slamming. Either way it sounds like a velocity problem. Is the pump too much for the system?
  • Larry (from OSHA)
    Larry (from OSHA) Member Posts: 728
    the pump

    is a Taco 007 and the valves are Honeywell V8043E. Will there possibly be an improvement in slamming when I change to pumping away and locating the valves on the return?

    Larry
  • dconnors
    dconnors Member Posts: 215


    Can I ask if the slamming is more prevalent when only one zone is calling for heat?
  • Larry (from OSHA)
    Larry (from OSHA) Member Posts: 728
    no real difference

    the system has three baseboard zones and an AQ475 reset controller. If I take off one spring on the valves there is no slamming. As long as the circulator is running, when a zone closes with both springs, it bangs. I think the original setup back in 1962 had slow acting motor open/motor close valves. Thanks for your input.
  • Mike Kraft_2
    Mike Kraft_2 Member Posts: 398
    You might try

    a pressure differential bypass valve.

    cheese
  • bob young
    bob young Member Posts: 2,177
    banging

    an air chamber or shock arrestor will eliminate any banging due to any quick closing valve be it a zone valve or flushometer
  • oil-2-4-6-gas
    oil-2-4-6-gas Member Posts: 641
    .

    its pretty common pratice where i am to remove 1 spring of the zone valve
  • Unknown
    Unknown
    Just Curious

    Since the drawing you posted is really that of Honeywell as indicated on their web site for the AQ475 control, this setup should work as intended. But this drawing does not show the expansion tank or air elimination device. Where is your expansion tank and what static fill pressure are you running?

    Glenn Stanton

    Burnham Hydronics
  • Larry (from OSHA)
    Larry (from OSHA) Member Posts: 728
    very perceptive

    Glenn,

    A little more background. The Weil Mclain HE series 2 boiler has a built in air separator with a tap at the top of the sections which goes to the compression tank. With the circulator on the return, air has always been an issue and I have maintained a rather high static pressure of about 20 lbs. in an attempt to keep the air from coming out of solution. The hope is that when the piping is changed to reflect the Honeywell drawing, and with larger headers etc., multiple problems will be solved including the cavitation issue on the indirect DHW tank circulator (that is a separate issue and thread).

    For some backround you may check this thread that dealt with the cavitation issue.

    http://forums.invision.net/Thread.cfm?CFApp=2&Thread_ID=16744&mc=11#Message104878

    Thanks for your interest and any input is greatly appreaciated.

    Larry
  • Boilerpro_3
    Boilerpro_3 Member Posts: 1,231
    Gravity flow is possible in a single pipe

    It happens! A positive shut off zone valve will stop flow through a pipe, but cannot stop flow within a pipe. Hot water flows to the top of the pipe and cold water settles to the bottom. With this temp difference flow is created in a single pipe. Add a few radiators or convectors and you can get alot of heat off a zone with a zone valve is shut off. Doesn't happen always, but it does happen. I believe the old gravity one pipe hot water systems operated completely based on this principle. STeamhead and a few others have seen these systems I believe.

    Check out the old B&G manuals...flow checks on both supply and return. This may look like a way to sell more product, but there is sound theory and experience behind it.

    Boilerpro
  • hr
    hr Member Posts: 6,106
    I would

    use a Grundfos 15-58 on speed one for the heat. Speed 3 for quicker DHW recovery on the indirect circ. 15-58's have an intergral check to prevent ghost flow as B-pro mentioned. Same price as a regular 15-42, by the way. Why not use them and take that potential out of the equasion?

    And I would still move the ZVs to the return side.

    The banging may be improperly supported pipes and hard to correct. Proper flow velocity and good zv placement will help.

    This article deals more with causes and cures for ghosts in the pipes :)

    hot rod

    http://www.pmmag.com/CDA/ArticleInformation/features/BNP__Features__Item/0,2379,13972,00.html

    To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"
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