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PH Level in steam boiler

I would like to know what will cause a higher than normal, lower than
normal PH level. Also looking for help in adjustment of this level. Thanks!!

Comments

  • Jamie Hall
    Jamie Hall Member Posts: 23,165
    Consensus seems to be around 8 is good; 7 to 9 is certainly reasonable. Higher seems to give foaming, and lower may result in more corrosion (may not, too).

    There are several products which one can add -- in small quantities -- to buffer the pH in a reasonable range.

    As a general sort of rule, the feedwater pH is what determines the pH level, assuming one isn't adding treatment. There isn't much happening inside a boiler which will alter pH.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • Erin Holohan Haskell
    Erin Holohan Haskell Member, Moderator, Administrator Posts: 2,276
  • ethicalpaul
    ethicalpaul Member Posts: 5,695
    I like to go higher than Jamie said. 10-11. You can even go way higher without foaming in a clean boiler, but there's probably little benefit.

    If you twist my arm I'll tell you that the ph isn't nearly as important as making sure you don't have any steam or water leaks in your system.
    NJ Steam Homeowner. See my sight glass boiler videos: https://bit.ly/3sZW1el
  • ChrisJ
    ChrisJ Member Posts: 15,588
    edited September 2021

    I like to go higher than Jamie said. 10-11. You can even go way higher without foaming in a clean boiler, but there's probably little benefit.

    If you twist my arm I'll tell you that the ph isn't nearly as important as making sure you don't have any steam or water leaks in your system.

    I'd rather leaks with a pH of 9+ over no leaks and a pH of 4.............

    But that's me.

    I also feel 7 is too low and 8 is iffy. I like 9, 10 is fine.
    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
  • Pumpguy
    Pumpguy Member Posts: 645
    In my experience, very high pH is corrosive to bronze pump parts.

    In my days as a service tech at Nash Engineering, anytime we had a vacuum pump or gas compressor with a high pH carryover, ALL IRON construction was specified. This meant no copper alloy to be present.

    I have also seen this corroded bronze parts in condensate and vacuum pumps used for steam heating systems. Again, this was traced to condensate pH being too high.

    Never was able to determine what the pH limit was, but I like to say maybe 9 or so.
    Dennis Pataki. Former Service Manager and Heating Pump Product Manager for Nash Engineering Company. Phone: 1-888 853 9963
    Website: www.nashjenningspumps.com

    The first step in solving any problem is TO IDENTIFY THE PROBLEM.
  • ChrisJ
    ChrisJ Member Posts: 15,588
    Pumpguy said:

    In my experience, very high pH is corrosive to bronze pump parts.

    In my days as a service tech at Nash Engineering, anytime we had a vacuum pump or gas compressor with a high pH carryover, ALL IRON construction was specified. This meant no copper alloy to be present.

    I have also seen this corroded bronze parts in condensate and vacuum pumps used for steam heating systems. Again, this was traced to condensate pH being too high.

    Never was able to determine what the pH limit was, but I like to say maybe 9 or so.

    I believe it also etches glass.
    But my opinion has been I'd rather replace the gauge glass than the boiler.

    So far.
    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
    ethicalpaul
  • ethicalpaul
    ethicalpaul Member Posts: 5,695
    Pumpguy said:

    In my experience, very high pH is corrosive to bronze pump parts.

    In my days as a service tech at Nash Engineering, anytime we had a vacuum pump or gas compressor with a high pH carryover, ALL IRON construction was specified. This meant no copper alloy to be present.

    I have also seen this corroded bronze parts in condensate and vacuum pumps used for steam heating systems. Again, this was traced to condensate pH being too high.

    Never was able to determine what the pH limit was, but I like to say maybe 9 or so.

    I guess we don't know if this is a residential application, but there's nothing a typical home boiler situation can do about the PH of condensate...how high could condensate be anyway?
    NJ Steam Homeowner. See my sight glass boiler videos: https://bit.ly/3sZW1el
  • ChrisJ
    ChrisJ Member Posts: 15,588

    Pumpguy said:

    In my experience, very high pH is corrosive to bronze pump parts.

    In my days as a service tech at Nash Engineering, anytime we had a vacuum pump or gas compressor with a high pH carryover, ALL IRON construction was specified. This meant no copper alloy to be present.

    I have also seen this corroded bronze parts in condensate and vacuum pumps used for steam heating systems. Again, this was traced to condensate pH being too high.

    Never was able to determine what the pH limit was, but I like to say maybe 9 or so.

    I guess we don't know if this is a residential application, but there's nothing a typical home boiler situation can do about the PH of condensate...how high could condensate be anyway?
    I honestly thought condensate, in a perfect world would have a low pH, of 4 or 5.
    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
  • Pumpguy
    Pumpguy Member Posts: 645
    I can't tell you how many times I have seen cast iron pump castings turned to graphite paste due to low pH.
    Sometimes this graphite layer can be 1/8" or more deep .

    The acidic condensate leaches out the iron, leaving the free carbon behind.
    Dennis Pataki. Former Service Manager and Heating Pump Product Manager for Nash Engineering Company. Phone: 1-888 853 9963
    Website: www.nashjenningspumps.com

    The first step in solving any problem is TO IDENTIFY THE PROBLEM.
  • ChrisJ
    ChrisJ Member Posts: 15,588
    Pumpguy said:

    I can't tell you how many times I have seen cast iron pump castings turned to graphite paste due to low pH.
    Sometimes this graphite layer can be 1/8" or more deep .

    The acidic condensate leaches out the iron, leaving the free carbon behind.

    But you've also seen condensate with a high PH?
    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
  • Canucker
    Canucker Member Posts: 722
    ChrisJ said:

    Pumpguy said:

    I can't tell you how many times I have seen cast iron pump castings turned to graphite paste due to low pH.
    Sometimes this graphite layer can be 1/8" or more deep .

    The acidic condensate leaches out the iron, leaving the free carbon behind.

    But you've also seen condensate with a high PH?
    If it has a high pH it's probably due to how clean the condensate is. It likely doesn't take much to buffer the solution
    You can have it good, fast or cheap. Pick two
  • dopey27177
    dopey27177 Member Posts: 887
    Me: In my time I found ph levels at 9 & 10 worked best in boilers.
    Some jobs where ph levels reached above 10 foaming occurred.

    Other chems to add were amines to prevent oxydation.

    Jake
  • Pumpguy
    Pumpguy Member Posts: 645
    ChrisJ said:

    Pumpguy said:

    I can't tell you how many times I have seen cast iron pump castings turned to graphite paste due to low pH.
    Sometimes this graphite layer can be 1/8" or more deep .

    The acidic condensate leaches out the iron, leaving the free carbon behind.

    But you've also seen condensate with a high PH?
    Yes, In one memorable case at a high school, the condensate had a yellowish tinge to it, irritated my hands, and had a slippery feel.

    The iron pump parts were fine but the bronze parts were all shot.
    Dennis Pataki. Former Service Manager and Heating Pump Product Manager for Nash Engineering Company. Phone: 1-888 853 9963
    Website: www.nashjenningspumps.com

    The first step in solving any problem is TO IDENTIFY THE PROBLEM.