Low pressure steam boiler

PsiVessel_B73

PsiVessel_B73

Columbia low pressure steam boiler is on for 2 minutes than off for 2 minutes. 
Operating set at 10 ( range 10 and differential at 5). Modulating set at 2.5.  
Boiler or steam is servicing heat exchanger that's 10 feet away. 

ScottSecor

Looks like a firetube steel boiler to me with a Powerflame burner. The burner gets fresh air through the ductwork. Steam to water heat exchanger supplies heated water to the air separator and the base mounted circulator pumps.

Did you have a question or concern that you need help with, or did you just want to show us a photo of your system?

ScottSecor

At first thought, it sounds like the boiler is grossly oversized for the load. Hopefully I am mistaken and at least one of the following might be something to investigate.

A. Is it possible that the steam to water heat exchanger only has partial demand. What does the this heat exchanger supply?

B. Is it possible that someone sized the steam boiler to supply a much larger load in the future and it never happened?

C. You could probably reduce the firing rate of the burner.

D. The steam piping looks unusual to me. Odd that the installer reduced the steam outlet size coming out of the boiler, then increased the size of the horizontal header, then drastically reduced the size of the drop header.

E. The hot water piping also looks unusual to me (near the steam to water hx). Someone ran 4" welded steel pipe for the inlet of the base mounted B&G pumps, they ran 2" threaded pipe to the hx inlet