The relief valve is there to protect the vessel and the people in the area as is the rupture disc.
Monkeys may monkey with the relief valve but the rupture disk is NOT ADJUSTABLE. As long as it is not painted or other wise tampered with it will still be there protecting the vessel and the...
I believe running with the drains open would be like adding recycle to the compressor so it may move the machine away from the surge line. It would also reduce the efficiency somewhat. There may be other considerations depending upon the plumbing of the drains and the gases involved.
