Shutting off your only downstream overpressure relief valve would be a big mistake.
However, if it is a single tank rig, and there is an octo, there is another relief that is through the octo...
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Shutting off your only downstream overpressure relief valve would be a big mistake.
I'm surprised that of all the things to worry about, you have focused on a free flowing regulator. Don't take that the wrong way, I'm not making fun or being a jerk. It's just that I've never considered free flows to be a big concern if it does happen, or even a high possibility of happening in the first place.
I worry about lots of other things before I worry about free flows