Flow sensor for RIMS tube safety

[bergerrings]

Just wondering if anyone has any flow monitoring equipment in their breweries. Flow meters are relatively easy to come across but I am after a device that can sense low or no flow and then activate/deactivate an electrical device. In my case, I would like to monitor the flow across my RIMS tube and when the flow dropped too low or stopped (approaching a stuck mash/pipe blockage/etc) the heating element in the RIMS tube would be disconnected. I know this is effectively done by the temperature set point of the RIMS tube temp probe but it would be nice to have a second layer of safety...can never have enough safety haha (safety of protecting our precious wort that is).
Back to flow meters, has anyone come across any good stainless steel sensors….that are in a home brewers budget?
Damo

[bergerrings]

This is a flow switch I am looking at:

http://www.ebay.com.au/itm/Stainless-St ... 3a77a75aed

It's a real cheapo from EBAY so not too sure on its quality...any inputs?
It should be pretty easy to use, I will just wire the 5V heater signal though the reed. The only possible issue is that there is a magnet in contact with the wort, does anyone think this could be a problem...or am I just being pedantic?

[fubar]

I didn't see any specs. Will it handle 170F?

[aleforce]

I found one in US $.. http://www.ebay.com/itm/ws/eBayISAPI.dl ... 1081190877 . Operating temps up to 130 C or 266 F according to the image http://0d.images22.51img1.com/6000/vivi ... fdc402.jpg. I'm going to give one a try. Thanks for the heads up.

[bergerrings]

I can't imagine temperature being an issue with a metal casing. I sent the ebay seller a message asking them what other materials are in the switch. Do you think it is just the usual 1/2 inch thread?

[clearwaterbrewer]

I think the inside has a restriction and spring, the restriction moving against the spring pressure during flow and setting off the magnetic switch is how it works... I bet a dollar that it will become easily clogged with a bit of grain....

I suggest a low pressure sensor as used on hot tubs(they have a similar rims tube), you can separate it by a foot with some sort of hose or line, and most of these are tunable for pressure...

-mike

[aleforce]

I just received the two that I ordered - all the way from China ; didn't take but a few days. They have 1/2" threads on them and are 3" long. I could see placing this on the return (between the RIMS tube and the Mashtun kettle) section of the RIMS and possibly using a triclover gasket with mesh screen (http://www.brewerygaskets.com/buna-screen-gaskets.html) before the sensor.

[clearwaterbrewer]

here are 20 different models of what I would try:

http://www.spadepot.com/shop/Pressure-S ... -C225.aspx

[bergerrings]

I ended up purchasing a tecmark 3029 but haven't wired it up yet...only just received my RIMS tube from Brewers Hardware. I intended to get a SPDT but I ended up with a SPST. I assume that when the preset pressure is reached the switch will close...correct? I plan to install it into a tee piece just after the throttling ball valve and simply wiring the RIMS tube signal wire through the switch. Sound about right?

aleforce...
How did you go with the flow switch? Did you end up getting that small screen?

[aleforce]

Haven't had a chance to install the sensor yet due to brewing some time sensitive beers and other schedule conflicts. Maybe next week I'll give it a try along with the mesh screen. I will definitely report back. Sorry it has taken so long...