Steam boiler water level / feed system

[BronYrAur]

I have 2 old 100 HP Kewanee 15 psi steam boilers in a basement and have been asked to replace one 1 of them. The condensate is all gravity return into a common header at the lower back of the boilers.

Do to access, my new boiler will have to be sectional and built in place. I have been told that I will never be able to match the water line, and therefore will need a boiler feed system.

I don't fully understand. Is this true? If so wouldn't the feed system have to serve both the old and new boilers? Would I be better off leaving the condensate alone and just replace both boilers?

 

[willard3]

You can match the waterlines old/new boiler by pads/pits and etc at the new boiler.

You can also add a pumped condensate system.

Why you are replacing only 1 boiler of a set of 2 is another question....are both old boilers the same age? Why are you replacing only one?

 

[BronYrAur]

They are both the same age - which is OLD. I am a contractor who has been asked to replace only one because it has major issues. The other one is undoubtedly not far behind. I have been thinking about offering a proposal for both and may wind up doing so. In case that doesn't fly, it sounds like I can just raise or lower the new one to match the water line. Is that it?

Let's assume that I will have to raise the new one. I will then have to pipe up from the condensate header into the new boiler. And now that I say that, my condensate header and all of the return line dumping into it must be full up to the water level, correct? The return header is very low - almost on the floor and it goes into each boiler down that low. I assume that the condensate header is "backed-up' high enough to match the boiler water line. In that case, having a new boiler that is raised off the floor shouldn't be a problem - as long as the water lines match.

Any other thoughts?

 

[BronYrAur]

I have also heard that although I can match the water line, i probably won't be able to match the water volume in each boiler. This will result in flooding of the smaller volume. makes sense to me. Any thoughts?

 

[imok2]

Steam systems found in apartment buildings, churches and schools with gravity returns and automatic feeders are especially famous for causing replacement boilers to flood because of this "system time lag" problem. The best way to solve this type of situation is to install a Hoffman boiler feed unit.
Boiler feed units are sized according to the steaming rate of the boiler vs. the system's time lag (which is different for every system!). Also remember we're not talking about all the water in the replacement boiler-only the amount found between the normal water line and the low water cut-off level.
If this sounds like a solution to your problem then go here:

http://www.bellgossett.com/Press/art.html

 

[chicopee]

Is the steaming rate of the new boiler matching that of the Kewanee boiler that is staying?

 

[BronYrAur]

I will match the lbs/hr of steam as closely as possible.