dema injector

[mikeexpress]

I have a dema injector that has no draw it is getting a good flow of water thru it but will not draw product. took apart and is clean inside both the water flow screw and the chemical draw adjustment screw are open all the way and still no draw.any other suggestions to look for short of replacrment of injector?

 

[ken-pro]

Re-install the injector and run the equipment. Close the water flow screw until the dema begins to draw product. If you get the water flow screw closed all the way and it still won't draw, then the dema needs to be replaced.

The principle is that the flow screw when closed creates restriction which allows suction - The dema will never draw with the flow screw all the way open.

 

[Scottswashandlube]

perfectly explained..... turn flow screw clockwise until you get suction.Over time I have experienced a build up of slime on the small spring and check ball that needs occasional cleaning.

 

[Back4More]

When you took the valve out of line, did you look through the two holes inside of the valve? There could be some debris in the ventouri (upper hole) as you look through the valve. If that is clogged, you can still have full water flow, but no suction. What size is the injector? What are you using it on? If it's an arch, are there any clogged nozzles?The only other thing I have seen is the ball inside the chemical block was rubber and not plastic and it swelled, not allowing suction. My thoughts are on my first suggestion, unless you plumbed the valve in backwards, because it definately won't work. Last thing to try is turning the chemical screw in about 3/4 of a turn from wide open. If it's out too far, the o-ring underneath it won't seal, and you will not draw either. Has the thickness of the product your using changed, making it harder to pull? Let me know if you need more help. Feel free to e-mail me off the list if you'd like.

http://www.demaeng.com/getFile.php?id=166&type=document

 

[Danny]

If you are checking your draw at the valve then everyone's suggestions are right on. If you are checking it by it not pulling chemical up the chemical line, then check if the footvalve is clogged. It is commonly forgotten.