During the last storm and flooding in my state, I was sitting with my wife for 4 days in a fair sized hospital.
I did get a tour of the boiler room while there. They said they don't get many requests for that and later said any who visit are some strange people....
They have 3 large steam boilers. They are staged for firing as the pressure drops.
The main lead boiler was running at about 85 PSI.
They then drop the pressure to 30 PSI for HW heating via converter/heat exchangers that are located near the boilers.
Being a visitor/tourist I didn't want to question this set up very much.
I understand the needed higher pressure for high temp/more BTU's heat transfer or lifting condensate.
But apparently 30 PSI is enough to do this.
To me it seems they could run the boilers at 40-50 psi and still get what BTU's are needed at 30 PSI.
The gas train is hi/low or modulating, not sure.
I have been to places where the pressure seems set quite high and when asked why, the answer is because that is where it always has been....the boiler pro set it there years ago.
I am just curious of this situation.