water feeder water, hot or cold

[Deleted User]

hot water to feed a steam boiler vise cold water..i know the mechanical mm feeders are rated for just 120 degrees and state cold water, but the uni-match feeder is rated for 175 degree water. wouldn't some air already be out of the water from the hot side? henry's law? wouldn't there be less chance of thermal shock?

jim bannister

Hot Water Feeding.....

Gerry,


A hot water feed will draw all of the minerals out of solution and plug up the feeder and the adjoining piping.

Thermal shock should not be a concern if the boiler is piped correctly, such as bringing the feed entrance into the return manifold below the water line or the hartford
loop. This way it will be tempered by the returning condensate and raising the temperature. No direct contact with the casting of the boiler.

Tony Conner

On Any...

...boiler, thermal shock can be an issue. However, the feeder on small, domestic steam boilers should be putting a very small amount of water into the boiler, on pretty rare intervals. I would think that if everything was working OK, and all of the condensate was making it back to the boiler (in decent time), the feeder should send water to the boiler maybe once or twice a week for a short time period, usually after blowing down the low water cut off. I would put this into the same catagory as softeners for make up water. If you have so much make up water on a straight heating boiler system, that scale formation is an issue, then you have serious problems elsewhere in the system that need to addressed - and soon.

steve_6

hot water feed

Why do they recomend you feed a process boiler with a hot water feed? Slant fin also recomends you feed their boilers with a hot water feed?