Originally Posted by Reelale
That's my concern as well. What is the fail-safe, other than making sure you have flow?
I tested mine as if I had a stuck mash by closing the valve and completely stopped the flow...
I use a BCS460 and the control, caught the temp before it reached 170f. (It spiked about 10f above the setpoint) That is out of the box setup (I can't take credit fur tuning), I'm not sure an Auber PID would do the same, the other thing is that my tube is 2" in diameter so it has a fairly large volume to "dampen" the temp spike.
What I haven't tested is what happens if the tube drains... say a hose breaks???
I think you HAVE to make sure that the tube will not empty from a siphon or something... my input is lower than the output and both are well below the level of the mash in the mash tun.
A flow switch on the output of the rims should work... But most I have seen don't seem to be rated very well for particulates in the flow... so, I don't know??? I don't have one, but I'm interested to see how it works out. (I know SawDustGuy has a flow switch, but I don't know the specs on his or if he has tested it with wort)
You can see the spikes in this graph where I closed the valve, then the temp leveled off to setpoint (157), then where I opened the valve back up. (The setpoint was 130 the first time I closed the valve)