Calculating the Energy savings of reducing steam boiler pressure

[BronYrAur]

I am trying to quantify the energy savings of reducing a boiler pressure from 140 psig to 125 psig. It is a 700 BHP Cleaver Brooks model 4WI-200-700-200 with a natural gas input of 28,576,000 BTUH. There is a feedwater economizer on the stack.

How can I quantify the savings?

 

[MortenA]

OK, get your point but a 3% reduction in energy loss is a 3% reduction in energy loss - although not in fired effect (hopefully)