steam boiler problem

ClaudeD

I am dealing with 3 low pressure weil-Mclain steam boilers connected in parrallel. Each boiler was equipped with 2 probe type low water cut offs. boilers ran out of water and 4 low water cut offs failed to isolate the boilers resulting in cracked and leaking boilers. boilers were replaced and each equipped with one float style and one probe style low water cut off. My problem is since then when boilers are operating, water disappears in one boiler shutting it down with low water cut off backing water up in next boiler over filling next boiler. then repeats this with next boiler like a yoyo. Cycle last 1 1/2 minutes alternating from boiler to boiler

Jamie Hall

How are the boilers piped together? The near boiler piping?

KC_Jones

Jamie Hall said:

How are the boilers piped together? The near boiler piping?

Pictures!

JUGHNE

Is there a feeder pump for each or all the boilers?

EBEBRATT-Ed

Code rules state that "two steam boilers should not be connected together below the water line" If they are you need a check valve on each boiler (not the best way) or a hartford loop on each boiler.

When you have boilers connected in parallel the idle (cooler) boilers will fill with condensed steam. The boilers that are running as soon as they build steam will try to force water out through there returns into the other boilers.


To manage these water issues you need hartford loops, correct near boiler piping and and overflow (spill ) traps on each boiler.


If you are using a condensate tank to feed water to the boiler this won't work either. A boiler feed tank may be needed with either feed water valves to each boiler or a feed pump for each boiler

ClaudeD

I understand what you are saying. I will try the check valves on each boiler as this will be the most financial resolution. It still leaves me wandering how the system worked well for near 80 years piped exactly as it is only difference is a float style LWC.

JUGHNE

Is this a pumped return?
Pictures?