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Air Test on Pex

john p_2
john p_2 Member Posts: 367
edited October 2019 in Gas Heating
Just completed all my near boiler piping to complete my hot water baseboard heating to my finished basement.
Having never used Pex or Manifolds before so I'm not sure if I can air test thru the manifold. And if so, can it be done with the flowmeters & actuators installed?

Comments

  • EzzyT
    EzzyT Member Posts: 1,294
    Yes the air test can be done thru the manifold. That’s how we do our testing, just don’t have the actuators installed.
    E-Travis Mechanical LLC
    Etravismechanical@gmail.com
    201-887-8856
  • john p_2
    john p_2 Member Posts: 367
    Ok thanks, so just tighten the caps that are located where the actuators will be?
  • EzzyT
    EzzyT Member Posts: 1,294
    You can leave them open if you want test all the loops at the same time.
    E-Travis Mechanical LLC
    Etravismechanical@gmail.com
    201-887-8856
  • HomerJSmith
    HomerJSmith Member Posts: 2,425
    edited October 2019
    Make sure any air vents are securely closed. That sure is a pertty installation. I'm a hillbilly at heart.

    Pump it up to 30 psi and monitor the gauge for 24 hrs. Know that a change in ambient temperature will raise or lower the gauge reading a few degrees.
  • john p_2
    john p_2 Member Posts: 367
    Thanks Ezzy
  • EzzyT
    EzzyT Member Posts: 1,294
    No problem John and what a beautiful mechanical room you’ve got there.
    E-Travis Mechanical LLC
    Etravismechanical@gmail.com
    201-887-8856
    Rich_49john p_2
  • john p_2
    john p_2 Member Posts: 367
    Thanks, I was laid off when I did it originally. Took me 3 months total but off & on between side jobs.
  • hot_rod
    hot_rod Member Posts: 22,018
    what pressure rating on the relief?
    I’d stay 5 lbs below that or remove it
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • john p_2
    john p_2 Member Posts: 367
    Yes, Hot Rod, just want to check and see if there was any missed Pex fittings or unsoldered joints.
  • mattmia2
    mattmia2 Member Posts: 9,572
    All the components will have max pressure specs, this will tell you what/how you can test. I like to put a piece of masking tape on the gauge and make a mark where i see the needle and 2 makes on the scale so i can line up the marks on the scale and correct for parallax. mirrored pressure gauges are expensive.
  • Larry Weingarten
    Larry Weingarten Member Posts: 3,272
    Hi, I sure do like the bend supports and medium sweep 90s! The flow will be sooo happy :p It isn't your question, but one thing that's been discussed here before is a preference for mounting the relief valve upright. Could be a code issue.

    Yours, Larry
    delta T
  • john p_2
    john p_2 Member Posts: 367
    Larry...which relief valve?
  • Larry Weingarten
    Larry Weingarten Member Posts: 3,272
    This one. ;)

  • rick in Alaska
    rick in Alaska Member Posts: 1,457
    It is actually written on the tag that says it is supposed to be installed vertically. I am pretty sure it is to keep debris from settling in it, and making it stick.
    Rick
  • john p_2
    john p_2 Member Posts: 367
    All piping complete, zone control unit installed and all thermostat wires ran to zone control....
  • DZoro
    DZoro Member Posts: 1,048
    Nice work, I miss soldering, great job!!!!
    D
  • john p_2
    john p_2 Member Posts: 367
    So having a hard time holding 60psi ait test...Found small leaks on PEX connections (screw connections) to the manifold. Now I get the supply side to hold 50 psi overnight but the return side goes down to 10 psi overnight.
    I'm confused as the manifold acts like a check valve between the supply & return piping because whenn filling one side it doesn't seem to pass thru causing me to have to test each side separately.
    I cant help but think there is a leak somewhere at the manifold because I walk thru all the rooms where baseboard is installed and hear no leaks....must be minot...any ideas?
  • john p_2
    john p_2 Member Posts: 367
    Ezzy, earlier you said just dont have the actuators on...why not?
    I am having a hard time withis air test...I did install the actuators and put air in but it seems as though something is acting like a check valve in that I'm not able to fill both S & R baseboard loops thru one side, either supply or return, why?
  • mattmia2
    mattmia2 Member Posts: 9,572
    edited October 2019
    you can fill it withe water and pump it up and see where the water comes out.

    is there a check valve in the pumps?
  • john p_2
    john p_2 Member Posts: 367
    Matt, I'm trying to avoid filling with water in case there is a leak. And as far as pumps go I'm isolating the test to just the s/r loops on the baseboard.
  • mattmia2
    mattmia2 Member Posts: 9,572
    Filling it with water then draining it isn't fun but it is usually easier than soaping each joint and staring at it for a while to see if any of the bubbles are getting bigger and missing getting a soap film on the part of the joint/valve/etc. that is leaking and still not finding the leak then having to rinse the soap off so it doesn't corrode anything.
  • Go with what @mattmia2 suggested, i.e. fill it with water. Air is a better test and you may not see any leakage with water, but if there is a big enough leak, at least you'll be able to see where it is.

    If you put the actuators on the manifold, it closes the valves. You want them open for testing. Since you installed the actuators, that's why you're not filling all the loops.
    8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour

    Two btu per sq ft for degree difference for a slab
  • john p_2
    john p_2 Member Posts: 367
    Ok, thanks Allan
  • john p_2
    john p_2 Member Posts: 367
    So air test held no problem, filled loops with water bur need to revent two of them.
    0uestion onthe EP manifolds....I'm trying push water thru supply side and vent thru the return side but when I use regular washing machine hoses on the ends of the manifolds they leak. I bought new hose, washers but they keep leaking...why??
  • EzzyT
    EzzyT Member Posts: 1,294
    You’ll need to double up on the washers on the hose ends
    E-Travis Mechanical LLC
    Etravismechanical@gmail.com
    201-887-8856
  • john p_2
    john p_2 Member Posts: 367
    Ezzy, yep. I actully had some that were thicker than usual and worked great. All loops filled, vented & working properly. Just some small punch list items left but heat works in the basement. Thanks
    rick in AlaskaRich_49
  • woobagooba
    woobagooba Member Posts: 186
    Hi John. Why the pex to copper to pex on the left side (supply and return lines)? Thanks
  • john p_2
    john p_2 Member Posts: 367
    I felt the PEX loops would look sloppy. I prefer things square, level and plumb....very mechanical.
    woobagooba