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Dirty Water
11-07-2006, 12:11 AM
I'm looking for a flowswitch that completes a circuit when it detects any flow.

The ones I've found so far do the opposite, they break the circuit when the detect too much flow.

Or perhaps one that I can modify to reverse the way it works?

PROFESSORRAIN
11-07-2006, 12:17 AM
Dirty check with your local fire sprinkler supplier they have just what you want.That probably easier said than done but you will find they have all kinds of items you can use in different situaitons.+ not real $$$$$$$$$.I see them seahawks are holding on!!!How do ya'll like that Bama boy( s.alexander)Go seahawks

Dirty Water
11-07-2006, 12:21 AM
The reason I'm looking is that I'm frustrated with the typical Pump/Pressure Tank/Pressure Switch setup to run an irrigation pump. There are too many times its a pain to get it balanced right and not have the pump cycle. (Drip zones etc).

I dislike just using a Pump Start Relay because many of our installs have yard hydrants.

My thought is to run constant 24v to the flowswitch, and then wire it before a pump start relay.

So, whenever the water starts to move (hydrant opens, or a zone comes on) the flowswitch would trigger and the pump would start. When the demand for water stops, the flowswitch would kill the current and the pump relay would close.

Seems to me that this would eliminate the pressure tank, and the constant hassle of fighting to get the GPM matched perfectly to the pump.

Dirty Water
11-07-2006, 12:27 AM
I'm wondering if something like this would work:

http://www.gemssensors.com/SpecTemplateStandard.asp?nProductGroupID=132

It doesn't specify if its normally open or normally closed.

Actually, I think this is exactly what I'm looking for.

http://www.gemssensors.com/SpecTemplateStandard.asp?nProductGroupID=137

http://www.gemssensors.com/gif/Catalog/PaddleDesign2.gif

Thoughts?

PROFESSORRAIN
11-07-2006, 12:36 AM
Dirty I got what you want,It is called MASCONTROL from ACQUATECH NORTH AMERICA check it out see if it might help.works well but on valve after it close a little bit.For a little back pressure.:drinkup: :waving:

Dirty Water
11-07-2006, 12:39 AM
I've seen similar products to the MASCONTROL put to use on regular domestic wells, They are very pricey.

I think for a simple irrigation pump, using Flow Swith and a PSR, with a pressure switch as a failsafe would work very well, for a heck of a lot less.

PROFESSORRAIN
11-07-2006, 01:17 AM
you got the flow switch that you need and it works both ways i believe

PurpHaze
11-07-2006, 09:26 AM
We use a flow switch for a booster pump on one of our stadium field systems. The booster is only activated when flow is detected in that section of main line. I know it works well but I don't know what brand it is. I'll try and check today.

Mjtrole
11-07-2006, 10:08 AM
I'm looking for a flowswitch that completes a circuit when it detects any flow.

The ones I've found so far do the opposite, they break the circuit when the detect too much flow.

Or perhaps one that I can modify to reverse the way it works?

Try flotronex.net they service a site we had a contract for, the flow switch was threaded into the discharge side of the pump, It made contact and turned on the relay.

speedbump
11-07-2006, 10:08 AM
You can get the Grid switches here. (http://www.pumpsandtanks.com/flow_switches.htm) They come on at 1gpm flow. They are also switchable. In other words the switch inside the unit has three contacts. One common and the other two are either normally open or normally closed. So you can use it to turn something on or off.

bob...

Wet_Boots
11-07-2006, 01:26 PM
McDonnell & Miller FS4-3 ~ is yet another one of the paddle-type switches, and a regular item on eBay auctions. I wouldn't try to do without a pressure tank, but with enough other controls, it may not need to be sized in the usual fashion. (you still want to prevent the possibility of short-cycling)

Dirty Water
11-07-2006, 09:02 PM
Boots, I was thinking about that too, you would want enough of a buffer to keep the pump from cycling from very low flow amounts.

A 5 gallon tank would probably work.

IRRITECH
11-08-2006, 12:22 AM
Why not run a cycle stop valve. works on very low flow and doen't require the engineering your looking at.

PROFESSORRAIN
11-08-2006, 03:11 AM
To get back to the Mascon you have no need for anything else for about $250.00 is what I pay for an 1.25".made for use with hydrants.