Vacuum pumps

flange

I'm in the process of reviving an old steam system. this system was originally fed from a central plant providing 200 pound steam and utilizing a reducing station in each building to drop to five pounds which was being downfed to perimeter fintube, some preheat coils, and some domestic converters. the condensate went down to a combination receiver, with two condensate pumps lead/lag, and two vacuum pumps lead/lag. the condensate was then pumped back to the boiler plant. this complex was broken up, and the building that im working on now has a new boiler, about 175 hp. we have tied in some of it a couple of years ago, removing the reducing station, and working with three pound steam. all is well. i am now bringing online more of the building which involves removal of another reducing station, and tieing in the steam mains and condensate return. vacuum pumps do not work, they leak bad. how important would it be to fix these. they also havent run in the original section and all is well.

MikeC_2

It depends

Seems if they were using a vac. pump before to return the condensate to a pump station to transfer it back,then the system must have been designed for vac. return.Take a walk with the flashlight and check the return piping sizes and configurations.Are they pulling condensate up small rises in the returns,smaller than usual pipes for condensate?Location of new boiler in relation to the old piping could also be a factor.

flange

no rises at all in any returns, walked this system twice while preparing the estimate to bring it back online. had to remove spence valves, had to convert high pressure condensate returns to low pressure condensate, had to "work" many old gate valves to get them to move, etc. i assume that the vacuum pumps would help the condnesate get back, as well as helping the steam get to where it needs to be, however, after tieing in the new piping during a weekend shutdown, i started this thing up monday, spent the whole day walking the system and found only one rad with a problem, and it was a cracked nipple. vacuum pumps at this time are not operable. temps were pretty low the last couple of days and all is well. my curiousity is how would the pumps running effect the system .

MikeC_2

Could be

that you never needed vac. in the first place.One of those situations when someone added those vac. pumps as "insurance" to that old system.Sounds like you did your homework by correcting the condensate piping and walking the system.Good job!