Dosing pump and self priming problem

[stiffljp]

I'm having a ton of trouble getting the dosing pump to self prime. The intended location is approximately 8 feet away and 2.5 feet above the liquid which thus far has been unsuccessful. I have also failed to get it running held around 2 ft above the water without any luck as well. The motor seems to be spinning without any trouble but I don't get any liquid out. Is there something I am missing?

It's a 2 pump unit and they are both set fine in the sockets, I am trying to run it in manually by pushing the button.

 

[burton14e7]

I had the same problem last night but then switched the tubes around. I had the intake as the outtake. I couldn't find documentation anywhere for that, even google searched peristaltic pumps to see if there was general engineering, but evidently the the right nipple is for intake and the left nipple goes to the sump.

 

[stiffljp]

thanks for the advice, unfortunately I've tried both sides to no avail. I think I read somewhere that the "short" tube was the intake but that happened to be the left on mine but my second pump tubes were almost completely equal.

 

[Matthias Gross]

if you watch the rotation of the rolls in the pump head it should be quite clear in which way the fluid will be pumped...

but thanks for the hint, we will add a note in the next instructions regarding the flow direction

 

[chippypah]

Fit a non return valve on the feed side of the pump.
Cheers
Pete

 

[jefft321]

What kind of non-return valve can you use? brand? I have seen some small plastic ones for air pumps, but I wasn't sure if you could use them in this type of application?

 

[chippypah]

That is what I use, they work great.
Cheers
Pete

 

[stiffljp]

That did the trick, thanks for the help.

Also with regard to the spinning of the wheels, I did see what direction they were going but I would have never guessed it would take so long for it to self prime. Granted it was going a decent distance but either way, instructions with greater detail would help.