Check Valve on Dosing Pump

[Terry4505]

I have been having an issue with air forming in the exit side of my dosing pump (Jebao DP4) on most of the heads. I am using new airline and this for dosing containers:

https://www.youtube.com/watch?v=zgie4bj_XgM

I added check valves to the end of the tubes today. Is there any danger in doing this? I cannot figure out how else to address the issue. The dosing pump sits above the sump and 2-ish feet from the dosing containers.

Thanks

 

[redfishbluefish]

Air has got to be getting in there somehow.

 

[Terry4505]

I just checked the lines this am, after having the check valves on for around 12 hours and bubbles are forming again. The air must be coming from somewhere other than the end of the lines.

I'll replace them all today and see what happens.

 

[reddog]

I have a problem with my new DP-4 on Pump 1. It's obviously defective, or the line is twisted in the pump. The pump is not making a good seal because the liquid drains back down the tube and back into the dosing container. The seller on Amazon says they are waiting on a response from the factory in China. I installed a check valve on the first pump just to see if it fixed the problem. Thus far, it seems to be holding the liquid right at the tip of the hose with no back siphon. I'm awaiting a response to see what they want to do about it. It's been so much trouble, I have almost just decided to leave the dang check valve on it and leave it be. Not sure if the check valve will cause any issues or get clogged up.

 

[itwired]

I have the same problem did you ever find a resolution?
thanks a million.

 

[TD13]

Following, considering a Jaebo Dosing Pump...

 

[itwired]

there dirt cheap thats for sure. If you don't mind tearing them apart or you get one thats flaw less then your good to go.

 

[Lenny_S]

What check valve did you use? I want to add one to prevent similar problems and to keep what I'm dosing from crusting up at the ends of my lines.

 

[AlbertGF]

I have a problem with my new DP-4 on Pump 1. It's obviously defective, or the line is twisted in the pump. The pump is not making a good seal because the liquid drains back down the tube and back into the dosing container. The seller on Amazon says they are waiting on a response from the factory in China. I installed a check valve on the first pump just to see if it fixed the problem. Thus far, it seems to be holding the liquid right at the tip of the hose with no back siphon. I'm awaiting a response to see what they want to do about it. It's been so much trouble, I have almost just decided to leave the dang check valve on it and leave it be. Not sure if the check valve will cause any issues or get clogged up.

Sorry, I know it's an old post but did you solve it? I'm having the same problem.

Thanks!!!

 

[Kungpaoshizi]

They're probably a 2 or 3 roller inside. So there's only 1 or 2 rollers actually making contact and pressing against the tube inside. This is why I got drew dosers from brs and said screw the rest. 4 rollers, so 3 are always engaged..

 

[AlbertGF]

Yes, Jebao pumps have only 3 rollers inside and depending on the position the rollers stop, there are no rollers sealing the line so the content is drained to the sump or back drained to the bottles.
I tried putting some tape on the rollers to make them wider and then they work for some months, after that time the tape break apart and the pump stops working again.
Now I have ordered the 4 withe head pump covers replacement to see if they have solved the problem. 15 to 20 days and 15$ to get the new covers. I'll wait....

 

[reefwiser]

Just put check valve on the outlet of the pump line. It will keep fluid in the line so it does not go back into the bottle and doses the correct amount of fluid into the tank.

 

[mcarroll]

+1

@Terry4505 and everyone....I know this is old, but I had a similar thread and dunno how I missed this one.

Same doser. My new airlines did almost the same thing – they formed bubbles seemingly out of thin air.

It wasn't back-siphoning in my case, I was noticing an accumulation of air around the pump head....usually on the in and out side, but not always and not always equally. Nobody offered even a guess as to the explanation, but after observing and living with it (let's burp the pumps again today...) what was apparently happening was that something about the brand-new Lee airline was causing some kind of reaction with my dosing liquid and micro-bubbles were forming out of the dosing liquid. Maybe something in the vinyl tubing causing surface tension to drop?

Whatever the case, after quite a bit of time...I think 2 or 3 gallons of Recipe 2 if I recall correctly...I made a switch to ESV for no related reason. Somewhere during the three gallons of ESV that I dosed (1 gallon kit that I diluted to Recipe 2 strength so I didn't have to mess with my doser programming) the doser stopped micro-bubbling and didn't even notice. I switched back to DIY Recipe 2 after the ESV was gone and have not had a repeat on the bubbles.

Here's the funny part. I recently started the third pump head for magnesium and it's doing the same thing (micro-bubbling) only worse....it's definitely back-siphoning too.

So I'm ordering some check valves today. Gonna put one on the dosing-container end in each container.