Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

Old Theater Steam system in WA

Options
pnwtech
pnwtech Member Posts: 3
in THE MAIN WALL
Hello there. HVAC tech here. I typically work on chillers so forgive my lack of knowledge. Had a service call today for an old theater probably built in the 20s. It has a low pressure CB steam boiler serving radiators in all of the admin offices. The call was for the condensate pump short cycling and the atmospheric vent on the condensate tank blowing out steam. I tried to study up quick after looking over the piping. From what I could see, the boiler is in the lowes point of the basement. It discharges 3psig steam into a header that travels roughly 4ft horizontally pitched upwards and then goes into a 7 story riser. Almost immediately off each branch from the mains there are drip leg type tees that have F&T traps on them. These are piped immediately back to the condensate return header and into the return pump reservoir that has the steaming atmospheric vent. None of those F&T traps had steam Temps in or out of them. The condensate return pump is switched by a probe type low water cutoff at the boiler with a glass sight glass. It controls a Warwick relay board that calls for the pump. I noticed the sight glass bobbing up and down. Roughly 1" and that relay board calling the pump in and out sporadically. I went up stairs to see what type of radiators were being used. Looks like basic floor radiators, see pics. They have a pipe going in and out. I believe it has a thermostatic trap on it. Please see pictures. My questions
-could that steam out of the atmospheric vent be cause by a check valve I found on the discharge side of the condensate pump failing?
-what type of system is this? I was expecting to see a main condensate return pipe. Instead it appears all condensate is handled by it flowing back to the main and hitting those F&t traps I described that are teed down off the main header. So would the condensate from all floors be piped to a common pipe then teed in to the main somewhere low that I'm not seeing? 
Thanks. 




Comments

  • pnwtech
    pnwtech Member Posts: 3
    Options
    Kiki
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 15,523
    Options
    If steam is blowing out the Boiler feed pump pump vent you have bad trap(s).

    It's two pipe steam with radiator traps.

    Try lowering the steam pressure to cut out the burner at 1.5-2psi maximum.

    You most likely have trap and venting issues in a neglected system.

    The boiler feed pump is probably short cycling because of the boiler bouncing water level

    But it can also short cycle because of a bad check valve(s) on the boiler feed pipe between the boiler feed pump and the boiler

Categories