ASME B31.9 & Safety Relief Valves

[flyrfan]

What is the specific criteria for providing pressure relief valves on building services piping according to B31.9?

I have a ground source heat pump system that currently does not have a relief valve on the well system. I was always under the impression that B31.9 required them if energy was transferred to any fluid in a closed loop system.

Thanks in advance.