OT - Flow Switch Recommendation

I need to find a different type of flow switch than the paddle style that has been used in the past: Basically a cantilevered thin piece of sheet metal that is attached to a MicroSwitch. With time, the blade fatigue off and end up downstream, usually never to be seen again unless they get caught up in a valve or pump.

The pressure rating is up to 100 psi and temperature rating need to be from 33 to 130 F in water and -20 to 60 F in a glycol/ water solution. It should shut off around 1 feet/sec and max flow is typically no more than 6 FPS.

Has anyone had some good experience with an alternative?

Could you possibly use a turbine flow meter?
Depending on the size of the pipe.

I know you get a little more than just an indication, but I've found the turbines to be near indestructable...
In fact it's what we use in our Glycol reboiler.

As for just a discrete signal, we use a pressure switch to indicate when we have flow due to it being a system that pressures up when flowing.

I have had good luck with this switch:

Efector

Check to see of it fits your specs.

Voltimus:
Pipe size is from 2" to 16", should have included that in the initial post so the turbine meters would get expensive. A pressure switch was considered but these would need to be a differential type at a number of locations as the operators open and close various valves manually depending on which flow path is needed for a given process.

Gerry M;
Efector was on my initial list of vendors to investigate, will bump them to the top when I start researching further.

You don't mention pipe size, so I'm not sure which of these might fit.

I've used both - very reliable because the contact paddle is not thin blade, it's thick and heavy. It can't leak due to construction. I've had several in for 6-7 years now, all are still functional. Only oddity is the way the setting is made, it's relative (higher, lower), not absolute. Reed relay is suitable for PLC DI but not for driving any real load.

for 2" line size and arger: "http://www.koboldusa.com/products_detail.asp?tmplt=4&cntrl=1&pgID=1&ptID=55&pID=120&pmp=PS&ptName=Target+%28Paddle%29

for 1/4" to 1.5" line size:
http://www.koboldusa.com/products_d...tID=55&pID=135&pmp=PSR&ptName=Target+(Paddle)

I have also used efector (mentioned above) and it works well.

Dan

Gerry M said:

I have had good luck with this switch:

Efector

Check to see of it fits your specs.

Click to expand...

This one gets my vote.

Chris

Similar operating principle to the Efector unit: http://www.fluidcomponents.com/