After messing around with mine (taking them apart, hooking them up backwards, running them at all different pressures, and finally using the washer with the faucet just barely cracked open) I can't see how _low_ pressure would make them shut off. High pressure shuts them off just fine.
How would low pressure make them shut off?
They certainly did fool me into thinking the inlet valve was bad.
But I was fooled only because I'm an ignoramus.
The only problem I see now is that if I open the faucet very little to keep the floodsafe from tripping (and then sticking shut!) when the washer is running, then if something does let go (inside the machine, perhaps), I will have a moderate leak that will still flood the heck out of my house if I don't catch it because the floodsafe won't stop it either.
I think I'll turn off the faucet when I 'm not doing the laundry.
Still better than beating the clothes on a rock.
floodsafe hoses ...will stop the water if your water pressure drops making you think your water valve is faulty.