Power boiler and Heating boiler

[tosif]

When we talk about mechanical design of boilers, ASME refers to two different sections for 'power boilers' and 'heating boiler'. Can anybody elaborate the difference between both types? How can I choose which code to be followed?

[arcpro]

Power boilers are high pressure ones in which the pressure of the steam generated by boiler is more than 15 psi and are constructed according to the rules of ASME BPVC Sec. I. A power boiler can be designed up to a maximum working pressure of 5000 psi.
Heating boilers are those in which the pressure of the steam or vapor generated is less than 15 psi. The pressure of hot water generated by this remains below 160 psi and temperature not exceeding 250 deg F. Heating boiler is constructed according to the rules laid in ASME BPVC Sec. IV.