HB Smith Series 28 water level problem

JSPAK

Here's what i got.2 hb smith 11 section series 28 steam boilers with a duplex boiler feed tank.The problem i got is that both boilers are continuously going off on manual reset low water 1 or 2 times a day.watching the boilers run,i watch water level start dropping as pressure rises(most likely water boiling off)pump turns on and starts feeding water from boiler feed tank into the boiler but just barely , somtimes bringing level so low boiler shuts off on primary boiler shutoff float . as soon as boilers do get to point where they are satisfied(7 psi steam pressure)and boilers shut off the water level rapidly falls sometimes going so low that it before equalizing it gets to the manual reset low water float .The pumps are the right size for the boilers and have been recently been replaced and are more than adequate.only problem i can see is that both equalizer lines are only 2 1/2 " and specs on the boiler installation from HB Smith call for 4".What i need is a good explamation for exactly what is going on and if the undersize equalizing lines are the actual problem. boilers are less than 10 years old . thx

ed wallace

HB smith

1st off drop the psi to 1 1/2 next equalizer is way to small steams leaving the boiler but condensate is not getting back soon enough the boiler needs to be repiped according to manufacturers specs

Warren Worth

HB Smith Series 28 water level issue

I cannot give you the facts, becasue I'm having a problem visualizing what part the equalizer is. If it's the pipe from the horizontal so called "header" down to below the water line of the boiler, I can almost assure you undersizing is the problem. Does the feedwater come into the equalizer? If so, I double my assurance. There is one more factor that everybody forgets (including me). The boiler has to be properly cleaned and skimmed so that all of the oil resulting from manufacturing the unit is out. Water levels don't hold under steaming or feeding with oil in the boiler. Check out "The Lost Art of Steam Heating" for a good read and great information.

Canadasteam

steam boiler operating water level stability problems

Greetings, have attended to a fair number of issues exactly as you described and in some of the cases I discovering a high conductivity rating in the boiler water and this high density conductivity was located approx. an inch below the operating water level. As the steam bubbles rose to break open across the surface this high density guck prevented even release and the water was lifting then would fall rapidly after the steam broke through it. Changes in the burner firing rate from high to low and burner cycling also tended to enhance the problem. I corrected this situation with a close to the surface skimming lance.

In other cases I found a problem with the velocity of the steam leaving the boiler to be very high and undersized main header piping was sometimes the culprit. The taller the steam system the worse the problem was. I would close the discharge header valve partially on the boiler under load and see if the problem stops or decreases, an easy experiment that might expose whats going on.

Hope this helps good luck.