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Yellowish water in drinkable tap

Roohollah
Roohollah Member Posts: 134
Dear Friends,

I have done a dental clinic drinkable piping with PEX A tube and and quick & Easy style of connection exactly like Uponor aqua pex. The fittings I used mostly were PPSU and I just used brass fittings an the walls for angle valves of lavatories and sink tap . The problem is that when the tap is closed for days and then it turns on there is a flow of dark yellowish water on a tap . Today, the dentist called me and asked me for a solution .I will go there to inspect the tap , angle valves and the Pex brass fitting and then to measure PH , temp and hardness.

According to the producer of the brass fittings , which announced that the PB is less than 37 % in those fittings , I may think of dezicification phenomenon in the system .

There fore, I look forward to hearing from you and your take on this problem .

Your time and support are highly appreciated ,


Sincerely,

Roohollah,

Comments

  • Larry Weingarten
    Larry Weingarten Member Posts: 3,078
    Hello, I think I'd send a sample to a lab and ask them to test for metals along with any bacteria they can find.
    Also, if there is a fitting you could easily cut out and replace, it might be nice to bring it back to your shop, and cut it open to look for damage or other clues.

    Yours, Larry

    ps. I might test the incoming water also. The documentation might be nice to have.
  • Roohollah
    Roohollah Member Posts: 134
    Dear Larry ,

    Warmly greetings from here to you and the friends out there. You are right , the water must be tested by lab ,but the problem here is that such a test is not available here around and it would be expensive . Of course, If all other clues do not help me to solve the solution , I will do it certainly.

    Today , I made a call to the brass manufacturer and asked them to support me ,to my surprise m they never have heard back such a situation , they mostly pointed at the pump room which supplies water which may contain iron and manganese and the pex pipe is so smooth and they never attach to the pipes wall ,so, it will concentrate highly when ever water stagnates for days.

    However, my younger brother ,who is using this products, has seen this problem at most of his projects .

    I have attached some photos of the wall mounted elbow which I guess it would be the culprit . I am going to test the mentioned system from point of entry and point of use to figure out the problem .

    Once more, thank you for taking the time to help me and indeed your recommendation encourages me to seriously solve the problem .

    Sincerely,

    Roohollah,




  • hot_rod
    hot_rod Member Posts: 19,921
    edited April 2018
    My guess would be a steel or ferrous metal component somewhere upstream. Cast iron pump, steel water mains, a black steel nipple used somewhere?

    Or

    In the springtime water sometimes gets a bit of a color from the minerals in the ground. Called turbidity, or the the optical clarity of water. Similar to smoke in the air, for example.

    Usually a very fin silt like component smaller than the eye can see. let it settle out in a glass for a day to see the fine layer.

    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
    Roohollah
  • nicholas bonham-carter
    nicholas bonham-carter Member Posts: 8,575
    edited April 2018
    Certainly you could draw off some water, and see what solids are settling out, and going to the bottom. Have a look for any iron pipe or connector in the supply.
    I imagine that the patients in the clinic do not want to see yellow water, when rinsing their mouths!! Good luck!—NBC
    Roohollah
  • AnthraciteEnergetics
    AnthraciteEnergetics Member Posts: 77
    I second the steel fitting theory. Including the nipples on tank water heaters which rust at the ends and give a burst of yellow hot water for a few days to weeks after install.
  • Roohollah
    Roohollah Member Posts: 134
    Dear Friends ,

    Thank you for the new recommendations and the time you have dedicated to support me .

    As regards supply water , I would tell you that the water is city water and it pipes to an old boiler room to supply to the floors . The complex has 14 units and they all receive their domestic hot , cold and heating from the boiler room , The entire piping for domestic cold and hot water is galvanized pipe and the collectors are as well , but the two of the units which now is a dental clinic has been renovated for four months and due to corroded risers piping , I equipped this floor with wall mounted boiler and changed the make up line from the boiler room to the flat with Uponor Pex pipe .

    As you guys stated earlier , Iron in the water is the main case for yellowish water . I have still been collecting more data to solve the problem or lessen it .

    One thing more, I have not used any cast Iron or galvanized nipples or fitting into the new piping installation , i just used brass tap Elbow and brass nickel nipple and the same brass nickel angle valves for the faucets .

    Is it a good practice to use an in line micron filter to trap impurity of the main supply water to the flat ?


    Once more, thank you in advance for your time and words of valuable advice ,

    Sincerely,

    Roohollah
  • Larry Weingarten
    Larry Weingarten Member Posts: 3,078
    Hello, It might be fun to take some of that yellow water and put a magnet into a clear glass of it and see if the water clears. If it does, you might be able to install a non-ferrous wye strainer that you put a strong magnet into, or some other configuration, like a filter housing with room for magnets inside. I didn't see much online commercially available. :(

    Still, running water through a 5 micron filter, then through some magnetic arrangement might do what you need.

    Yours, Larry
    RoohollahCLamb
  • Canucker
    Canucker Member Posts: 721
    We had an issue with a containment vessel rusting that held solvent we needed to use. We had to go to an absolute 0.2 micron filter to remove the rust, 5 mic just didn't quite get it clean enough. YMMV
    You can have it good, fast or cheap. Pick two
    Roohollah