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Steam condensate

Long time listener first time caller. I have a question about steam condensate. I have a hospital here in town (Helena MT) that is running 95 psi steam. There was a 4 story addition added about 12 years ago. They are bringing 95 psi steam up to the penthouse and knock the pressure down to lets say 15 psi up there to heat their loads. The condensates then drain into a condensate unit and pump up about 3 feet and over 20 feet before it drops 5 stories to the boiler room. Why would there be a pumped condensate receiver when it is 5 stories above the boiler room and they had room to gravity drain it? Any ideas would be greatly appreciated.


  • pecmsg
    pecmsg Member Posts: 3,532
    Because the boilers operating at 95#’s
    the condensate is much lower pressure.  
    Mad Dog_2
  • bburd
    bburd Member Posts: 576
    edited January 25
    Right. The static head from draining down five stories is about 22 psig, not enough to put the condensate back into the boiler. It has to be pumped to overcome the 95 psig steam pressure.

    Mad Dog_2
    EBEBRATT-Ed Member Posts: 13,097
    In that case I would have gravity drained it to a boiler feed tank in the boiler room
  • sorensenplumbing
    sorensenplumbing Member Posts: 2
    I should have stated that at first. It does drain into a vented condensate receiver where the old boilers used to be. It does run horizontally across a pipe bridge before it gets there and the steam line has main line traps in it along the way. The whole boiler plant was redone about 6 years ago and things may have changed in the design when that was done. The condensate pump is a 20 psi discharge pump so it still couldn’t overcome the 95 psi in the boilers. I appreciate the feedback, thanks!
  • Mad Dog_2
    Mad Dog_2 Member Posts: 3,869
    Yeah because the concern there is your gonna have HP steam running amok in your returns if even more trap fails...just curios what are you supplying w the HP steam?
    Autoclaves, Sterilization? Process equipment?  Mad Dog. 
  • retiredguy
    retiredguy Member Posts: 681
    edited January 26
    There may be a lot more to the explanation of this steam system that you wrote such as does it utilize a deaerator, which it should, since it has been updated a few years ago. The selection of the condensate pump system was selected by the the company that did the building engineering for the new addition. They could have opted for gravity return or pumped return of the condensate depending on many factors. Either type of condensate return would be acceptable depending on the piping and how it is configured as it returns the condensate to the boiler room. I have seen both types utilized. The pumped return system in a large building is usually more cost effective since a smaller diameter pipe can be routed anywhere it has to go. It is cheaper and easier to install.