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Proper pH of a steam boiler

I have a customer that is being told by their chemical company that the pH of their boiler needs to stay between 11 and 13. This is a Weil McLain cast iron sectional steam boiler.

On my first visit I found they were maintaining the pH between 11 and 13. My litmus paper read closer to 14. They were having bad foaming and carryover. Flushing the boiler resolved the issue and I informed them it needs to stay between 7 and 9, as stated in the manual.

The chemical company is telling them I am wrong and it needs to be 11-13.

So I am posting this here so I can show it to the customer.

So, what is the pH in a steam boiler supposed to be?
Never stop learning.

Comments

  • Jamie Hall
    Jamie Hall Member Posts: 23,275
    I'll go with 7 to 9.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
    Tinman
  • ChrisJ
    ChrisJ Member Posts: 15,664
    Personally, I like 9-10 but 8 is fine. 7 is on the low side in my opinion.

    11 is pushing it and anything above that there will be issues.

    I also believe a high PH is known to etch the gauge glass over time.
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • Chris_L
    Chris_L Member Posts: 336
    Well, here is what one Weil MClain installation manual says (EG & PEG Series 5):
    Filling steam boilers
    1. Fill to normal waterline, halfway up gauge glass.
    2. Boiler water pH 7.0 to 8.5 is recommended.
    3. Follow skimming procedure.
  • The manufacturer’s instructions should be more correct than anything the chemical company would say. Unless this boiler is generating steam for a process, and a lot of new water has to be added constantly, I would advise against any chemicals, unless there is a fresh water chemistry problem. Rhomar would be a better judge of better living through chemistry.
    A few Steammaster tablets might be good however, if the incoming water is acidic, and might make the customer feel better.—NBC
  • ethicalpaul
    ethicalpaul Member Posts: 5,701
    Ever since having to replace my rotted condensate return nipple and Hartford loop, I've been trying to keep mine about 10 but I am working to balance rough boiling/carryover (I wouldn't call what I have foaming)

    I actually have a hard time discerning between the colors for 9 and 10 on my litmus strips anyway :sweat_smile:
    NJ Steam Homeowner. See my sight glass boiler videos: https://bit.ly/3sZW1el
  • KC_Jones
    KC_Jones Member Posts: 5,736
    At that PH I bet it is foaming like crazy. I wouldn't argue with them I would put the ball back in their court.

    Ask them to please stop the foaming in the boiler and see what they say. It's a fact that high PH will cause foaming and improper performance, so since they are so knowledgeable ask them how to have high PH and not foam.

    I'm not a pro, and even I know this stuff, I've seen it myself. Bring the PH down, and the boiler smooths right out.
    2014 Weil Mclain EG-40
    EcoSteam ES-20 Advanced Boiler Control
    Boiler pictures updated 2/21/15
    ethicalpaul
  • DanHolohan
    DanHolohan Member, Moderator, Administrator Posts: 16,525
  • DavidMitten
    DavidMitten Member Posts: 16
    I used to be a paint detackification engineer. Try looking that one up on Google! It is an industrial water process. I also managed cooling towers, humidification systems, chillers, and portable boilers.
    Without knowing what the water quality of a system is, I would advise keeping the pH at about 9. If it gets up to 10, that is ok. If it is at 8, that is ok too.
    The higher pH passivates the metals in the system, thereby limiting corrosion.
    It can be hard to keep a system pH up at 11 or higher. However, a pH at those higher numbers is like doing a "caustic boilout".
    It will clean lots of stuff off the pipes and boiler and everything else and you probably will get foam.
    The natural process of a system cycling(In other words, in the case of a boiler heating and cooling repeatedly)will raise the pH of a system. So, unless a system is very acidic, I would not consider adjusting pH.
    One other thing I will mention about pH testing is that you can buy 2 or 3 pH paper kits. 1 will test for general pH. The other 2 can have much more limited ranges such as pH 7-8.5 and pH9-11. You can buy kits such as that from Cole-Parmer or Fisher Scientific or something. It beats guessing every time!
    ChrisJ
  • DanHolohan
    DanHolohan Member, Moderator, Administrator Posts: 16,525
    Thanks for your insights.
    Retired and loving it.
  • Canucker
    Canucker Member Posts: 722
    > @ChrisJ said:
    > Personally, I like 9-10 but 8 is fine. 7 is on the low side in my opinion.
    >
    > 11 is pushing it and anything above that there will be issues.
    >
    > I also believe a high PH is known to etch the gauge glass over time.

    You're correct on the glass. The glass is dissolving and clouding up
    You can have it good, fast or cheap. Pick two
    ChrisJ
  • ChrisJ
    ChrisJ Member Posts: 15,664
    > @Canucker said:
    > > @ChrisJ said:
    > > Personally, I like 9-10 but 8 is fine. 7 is on the low side in my opinion.
    > >
    > > 11 is pushing it and anything above that there will be issues.
    > >
    > > I also believe a high PH is known to etch the gauge glass over time.
    >
    > You're correct on the glass. The glass is dissolving and clouding up

    I made the decision a long time ago that I'd rather replace the gauge glass than the boiler. So far though, in 8 years no issues.
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
    trivetman
  • Jamie Hall
    Jamie Hall Member Posts: 23,275
    ChrisJ said:

    > @Canucker said:

    > > @ChrisJ said:

    > > Personally, I like 9-10 but 8 is fine. 7 is on the low side in my opinion.

    > >

    > > 11 is pushing it and anything above that there will be issues.

    > >

    > > I also believe a high PH is known to etch the gauge glass over time.

    >

    > You're correct on the glass. The glass is dissolving and clouding up



    I made the decision a long time ago that I'd rather replace the gauge glass than the boiler. So far though, in 8 years no issues.

    If the glass is being clouded by the water, the pH is too high. And may I add... if the pH is that high, the boiler water is hazardous (in water treatment, we regard anything at or over 11 as hazardous) and if there is a discharge -- say from a blowdown, or draining, or skim, never mind a pressure relief valve -- you must wear full wrap eye protection and gloves as a minimum.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
    Canucker
  • ChrisJ
    ChrisJ Member Posts: 15,664
    > @Jamie Hall said:
    > > @Canucker said:
    >
    > > > @ChrisJ said:
    >
    > > > Personally, I like 9-10 but 8 is fine. 7 is on the low side in my opinion.
    >
    > > >
    >
    > > > 11 is pushing it and anything above that there will be issues.
    >
    > > >
    >
    > > > I also believe a high PH is known to etch the gauge glass over time.
    >
    > >
    >
    > > You're correct on the glass. The glass is dissolving and clouding up
    >
    >
    >
    > I made the decision a long time ago that I'd rather replace the gauge glass than the boiler. So far though, in 8 years no issues.
    >
    > If the glass is being clouded by the water, the pH is too high. And may I add... if the pH is that high, the boiler water is hazardous (in water treatment, we regard anything at or over 11 as hazardous) and if there is a discharge -- say from a blowdown, or draining, or skim, never mind a pressure relief valve -- you must wear full wrap eye protection and gloves as a minimum.

    Like I said I run ,9-10 but id rather high than low.

    I've never needed gloves and I wear glasses.
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • Jamie Hall
    Jamie Hall Member Posts: 23,275
    "Like I said I run ,9-10 but id rather high than low.

    I've never needed gloves and I wear glasses. "

    At 10 you're probably alight. Skin may feel a bit slippery if you get too much on you -- that's the hydroxide dissolving it and making it into soap (think lye plus fat equals soap). The cornea of the eye is the problem. And the wrap arounds are to prevent any splashes from getting into it.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • ChrisJ
    ChrisJ Member Posts: 15,664
    > @Jamie Hall said:
    > "Like I said I run ,9-10 but id rather high than low.
    >
    > I've never needed gloves and I wear glasses. "
    >
    > At 10 you're probably alight. Skin may feel a bit slippery if you get too much on you -- that's the hydroxide dissolving it and making it into soap (think lye plus fat equals soap). The cornea of the eye is the problem. And the wrap arounds are to prevent any splashes from getting into it.

    Between me and you, I try to keep boiler water out of my eyes. The whole, rust and 212f thing and all ...

    :)
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
    Intplm.
  • Mike_Sheppard
    Mike_Sheppard Member Posts: 696
    I have found that following the manufacturer’s instructions generally works pretty well.

    The customer understands now that 11-13 is too high. The last visit I made I found it around 8.5. Matching the chemical companies recent records.

    Much better operation and no more breaking gauge glasses.
    Never stop learning.
  • ksd99
    ksd99 Member Posts: 77
    How do you test the PH?
    New owner of 1 Pipe Steam Boiler - learning all I can- no real steam pro in S.W. Michigan - if you know of 1 -let me know.
  • Jamie Hall
    Jamie Hall Member Posts: 23,275
    Hydrion pH test strips. Amazon.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • ksd99
    ksd99 Member Posts: 77
    Buying now. Thanks.
    New owner of 1 Pipe Steam Boiler - learning all I can- no real steam pro in S.W. Michigan - if you know of 1 -let me know.
  • Mike_Sheppard
    Mike_Sheppard Member Posts: 696
    edited March 2019
    Never stop learning.
  • ksd99
    ksd99 Member Posts: 77
    @Mike_Sheppard thanks mike.
    New owner of 1 Pipe Steam Boiler - learning all I can- no real steam pro in S.W. Michigan - if you know of 1 -let me know.
  • PMJ
    PMJ Member Posts: 1,265
    As @DavidMitten said, the natural process of repeatedly heating and cooling raises the PH. It doesn't just keep going higher and higher, but definitely does not go acidic on its own if no new water is being added. So the best water you can run in a boiler is water that goes in once and stays there. There should be no reason to add any chemicals as my Bryant manual states. It also says don't dump it out every year. What is already in there is way better for it than what comes out of the tap. My results clearly show they were right back in 1956. The longer the resident time of the water in the boiler the better. Fix the leaks!

    Since my initial startup this season when I added a gallon or two after checkout I have not added any water. I verify the LWCO is working and keep the supply valve off. The nice big boiler has plenty of extra capacity to do many LWCO blowdowns without refilling. I am also convinced that natural vacuum operation which dramatically reduces the exchange of air between the inside of the system and the heating space also reduces water consumption and therefore corrosion. Open vented systems doing fewer cycles with longer burns which backfill the entire system with dry air from the living space every cycle and then exhaust it surely require more water. Running that way may humidify the living space, but I bet those boilers and pipes wish that be done another way.

    1926 1000EDR Mouat 2 pipe vapor system,1957 Bryant Boiler 463,000 BTU input, Natural vacuum operation with single solenoid vent, Custom PLC control