CGA S 1.3 Flow Primary and Secondary Requirements

[Engineer_M]

I am new to understanding the CGA code. I see that it provides 2 flow requirements. When selecting a relief valve, which requirement needs to be met?

It was my understanding that the reclosing relief device, aka pressure relief valve, needs to only meet the system's primary flow requirement. The burst disk needs to meet the secondary flow requirement. Can someone correct my understanding here?

Also, what if my vessel does not have a burst disk, is that case, it is ok to just meet the system's primary flow requirement?

Thanks!