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Pressure test manifold and connected loop?

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cloudd
cloudd Member Posts: 48
edited April 2023 in Radiant Heating
I have an Uponor 12 loop stainless steel manifold.

*All of my loops have been individually pressure tested at 100PSI successfully before boarding of drywall*

*I will be installing the correct elbows to move the red pex onto the plywood.*


I would like to pressure test all of my loops connected to my manifold as one system up to the manifold at 100PSI to make sure a drywaller did not put a screw through any of my pex before taping and mudding. I just want to be sure I won’t have a problem before I move forward.

Can I manually open all of the balancing valves and connect a pressure gauge to the drain valve on the manifold and fill the system with 100PSI while the supply and return lines are closed to pressure test?

The problem I am having is that the gas pressure gauge I have appears to have a finer thread than the manifolds’s drain valve. Is the possible? I can only turn my reassure gauge 1/2 a turn onto the drain valve.  See pictures.


Is their and easier way to do this pressure test of the manifold and loops?




Comments

  • hot_rod
    hot_rod Member Posts: 22,262
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    That is a garden hose thread on the manifold valve. The gauge is a NPT thread.

    A connection similar to these, female garden hose to 3/4 male

    The one below is 1/2” NPT, they should have a 3/4 NPT male.

    Ace hardware, any of the box stores
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
    cloudd
  • cloudd
    cloudd Member Posts: 48
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    Can pipe dope be used on the 1/2” pex compression fittings that go into the manifold or should something else be used?
  • Big Ed_4
    Big Ed_4 Member Posts: 2,806
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    It would be best to pressurize the system with water .Striker plates are on you . If they hit one everyone would know ..

    Noticed a mistake on your manifold the way it is piped , Flip one of them to reverse return which would equalize the pressure drops across the takeoffs

    There was an error rendering this rich post.

    GroundUp
  • hot_rod
    hot_rod Member Posts: 22,262
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    cloudd said:

    Can pipe dope be used on the 1/2” pex compression fittings that go into the manifold or should something else be used?

    Are there rings on the Pex adapters? No need to pipe dope them.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • cloudd
    cloudd Member Posts: 48
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    hot_rod said:
    Can pipe dope be used on the 1/2” pex compression fittings that go into the manifold or should something else be used?
    Are there rings on the Pex adapters? No need to pipe dope them.Is it bad if I did?
  • hot_rod
    hot_rod Member Posts: 22,262
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    Are there o rings on the fitting that goes into the manifold? Pipe dope on that connection could cause a problem. A pressure test will tell.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
    cloudd
  • hot_rod
    hot_rod Member Posts: 22,262
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    It can be overwhelming, but not insurmountable. Keep up the good work caring for your mom and her place
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • cloudd
    cloudd Member Posts: 48
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    Big Ed_4 said:
    It would be best to pressurize the system with water .Striker plates are on you . If they hit one everyone would know .. Noticed a mistake on your manifold the way it is piped , Flip one of them to reverse return which would equalize the pressure drops across the takeoffs.


    The manifold is in the basement. I have striker plates in most areas but not possible behind the manifold wall in my bathroom ceiling where all pipes from one side of the house cross. The ceiling has been dropped a 2x4 width (1-1/2”) and the pipes are within this area. The basement is completely finished except for a few areas with drop ceiling. I don’t want to lose anymore ceiling height I’m already at 7’ in the bathroom area.


    Please explain the mistake in more laymen terms. Perhaps a sketch.
  • cloudd
    cloudd Member Posts: 48
    edited April 2023
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    hot_rod said:
    Are there o rings on the fitting that goes into the manifold? Pipe dope on that connection could cause a problem. A pressure test will tell.

    There are O rings on the compression fitting connections. The plumber who just installed my Bosch singular 5200 told be to use pipe dope. I should have asked here first. Anyways I am testing at 60psi at the moment and it seems good for an hour. I will leave it until tomorrow. 

    If the seal is good and the psi is stable should Move forward and leave compression fittings with the pipe dope on the O ring seals or should I remove the pipe dope before moving forward? 

    Will the pipe dope damage the seals overtime vs no pipe dope?


  • mattmia2
    mattmia2 Member Posts: 9,749
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    If your emitters are installed be careful to check their specs. They usually are rated for a lot less than 100 psig. Make sure you don't exceed the rating of any of the components. Check the specs on the manifold too.
  • hot_rod
    hot_rod Member Posts: 22,262
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    If he just put a small dab on the threads you are fine. If he coated the o ring with pipe dope, not so good. It would be a job to disassemble and clean them all off. See how the pressure test goes.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • dko
    dko Member Posts: 611
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    No one who pipe dopes everything and anything with a thread only puts a dab.
  • cloudd
    cloudd Member Posts: 48
    edited April 2023
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    I ended up testing at 90 PSI. Good thing I cut it off there. The uponor manual says 100PSI max. There are no other components other that the HelioPEX and the the uponor manifold with compression fittings in the psi test.



    I did coat the compression fittings and o-ring with blue magic pipe dope as per the plumbers instructions (that was a mistake) There is no water in the system and I have not had any water in the system. I thought about the pipe dope in the system afterwards (closed system) and thought that pipe dope in the system/boiler might not be good idea as it would be an impurity circulating in the water through the system.


    So perhaps I should save myself the future hassle / expense (pipe dope circulating through the combi causing corrosion…rust?) and clean all of the pipe dope off of the o-rings and compression fittings.






  • Big Ed_4
    Big Ed_4 Member Posts: 2,806
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    Your manifold is piped Direct return . The first loop would have the highest pressure drop and the last would have the least . By flipping one of the manifolds it will change it to a reverse return system . Now the first loop would be the first supply and the last return . Reverse return equalizes the pressure drop in an manifold ..

    Helps you with the balance .

    There was an error rendering this rich post.

  • Big Ed_4
    Big Ed_4 Member Posts: 2,806
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    I always keep the system charged with water , it keeps the other contractors honest ...

    There was an error rendering this rich post.

  • cloudd
    cloudd Member Posts: 48
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    Big Ed_4 said:
    Your manifold is piped Direct return . The first loop would have the highest pressure drop and the last would have the least . By flipping one of the manifolds it will change it to a reverse return system . Now the first loop would be the first supply and the last return . Reverse return equalizes the pressure drop in an manifold .. Helps you with the balance .

    Is this a preference but not a must. Is this used to simply the balancing process but optional?


    I have not noticed this on other setups and no one has mentioned it except you.
  • Big Ed_4
    Big Ed_4 Member Posts: 2,806
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    Maybe not, just trying to help. ...

    There was an error rendering this rich post.

  • cloudd
    cloudd Member Posts: 48
    edited April 2023
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    So far I have cleaned off (o-ring and compression fitting) 12 of the 24 connections using Q-Tips, tootbrush, paper towel and a vacuum. It’s a little painful but now I don’t have to think about pipe dope circulating through my new combi boiler. 


  • GroundUp
    GroundUp Member Posts: 1,926
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    The whole "reverse return" thing is hogwash with radiant like this. The pressure drop between the first and last loop is immeasurable.
    hot_rodmattmia2cloudd
  • pecmsg
    pecmsg Member Posts: 4,893
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    GroundUp said:
    The whole "reverse return" thing is hogwash with radiant like this. The pressure drop between the first and last loop is immeasurable.
    But it’s still Good Piping Practice!
  • hot_rod
    hot_rod Member Posts: 22,262
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    Just label all the tubes if you stagger them so you know which two ends are the various loops
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • GroundUp
    GroundUp Member Posts: 1,926
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    pecmsg said:


    GroundUp said:

    The whole "reverse return" thing is hogwash with radiant like this. The pressure drop between the first and last loop is immeasurable.

    But it’s still Good Piping Practice!


    What makes it "good piping practice" when it serves no functional purpose? All it does is confuse the next person to work on it because the loops aren't piped as they should be.
    TonKacloudd
  • TonKa
    TonKa Member Posts: 104
    edited April 2023
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    Reverse return on a manifold - especially one with flow meters and balancing valves - sounds like an uneccesary complication, IMO.
    mattmia2cloudd
  • Big Ed_4
    Big Ed_4 Member Posts: 2,806
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    All parallel systems should be RR . Our mistakes are found in the Dead of Winter . Normally someone ends up buying a bigger circulator or the expensive manifold . Zone valves are normally piped in parallel , The end zones will dog to the first .

    Twin in hot water heaters direct return , what will happen ?

    There was an error rendering this rich post.

  • mattmia2
    mattmia2 Member Posts: 9,749
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    Unless your manifold is undersized the pressure difference from one end of the manifold to the other will be negligible.
  • Big Ed_4
    Big Ed_4 Member Posts: 2,806
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    Everything would take the short cut ...

    There was an error rendering this rich post.

    cloudd