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Leaking condensate tank / boiler feed tank

Observed a slow leak on a 30 gallon boiler feed tank that serves a WM LGB 910k steam boiler. The feed tank (Sterlco) is working properly but one side wall has degraded at the waterline and has begun leaking. It is only about 10 years old and the pump is still working fine. I flushed it out today and cleaned the sight glass but I'm worried the leak will expand.

The tank is constructed of welded steel and I'm thinking of just welding a patch over the problem area to extend the life. It certainly seems like the more economical choice over wholesale replacement right now and I can better plan a replacement in the off season.

Any recommendations on this plan? I know it's a bandaid and not the best long term solution.

Comments

  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 7,817
    Welding is a great way to solve your problem. I know some welders that will disagree with this statement.
    I know it's a bandaid and not the best long term solution.

    That could be a permanent solution if you find the right welder.
    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics
  • Pumpguy
    Pumpguy Member Posts: 654
    Unfortunately, 10 years life on a 3/16" wall welded carbon steel condensate return or boiler feed tank is very common, IME.

    Cast iron tanks frequently come with a 20 year warranty against corrosion failure, so those are my preference.

    I am seeing Stainless steel tanks, and even pump housings more often these days. Only caveat with stainless steel is to avoid water treatment chemicals ending in ......ide.

    I've often wondered if that FLEXTAPE stuff we see Bill Swift pitching on TV would be a useful, albeit temporary repair for something like this?
    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.
  • veteransteamhvac
    veteransteamhvac Member Posts: 73
    Pumpguy said:

    Unfortunately, 10 years life on a 3/16" wall welded carbon steel condensate return or boiler feed tank is very common, IME.

    I've often wondered if that FLEXTAPE stuff we see Bill Swift pitching on TV would be a useful, albeit temporary repair for something like this?

    Funny you should say that as the leak is along the side of the tank facing the wall so the customer had already taped it up using gorilla tape and then jammed some wood in there to hold it all. Seemed to stem the flow quite a bit but the wall itself has the give of thick rubber.
  • veteransteamhvac
    veteransteamhvac Member Posts: 73

    Welding is a great way to solve your problem. I know some welders that will disagree with this statement.

    I know it's a bandaid and not the best long term solution.

    That could be a permanent solution if you find the right welder.
    We are seriously working that as a solution. The customer has taken the initiative to contact Sterlco to see if they sell just the tank itself, though I'm wondering if CI is a better idea. Though code in the city here requires a certain size for this size of boiler.
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 15,513
    CI is better. The other thing to investigate is the amount of MU water added to the system.

    Adding a lot of make up water to lukewarm condensate in the presence of oxygen (the tank is vented) seems to rot steal pretty quickly.

    Hopefully the tank wall has enough left to be able to be welded without blowing a big hole in it
    veteransteamhvac