Neptune flow sensor impact

[Johnseye]

Does anyone know if the Neptune flow sensor decreases potential flow because of potential resistance of the pinwheel used inside the pipe or by any other constriction within the device itself?

 

[ca1ore]

It absolutely does. Cannot say exactly how much, but I always upsize the sensors to try to minimize back pressure.

 

[vetteguy53081]

It should not but I would address that with Neptune systems

https://www.neptunesystems.com/support/contact-support/

 

[Johnseye]

It should not but I would address that with Neptune systems

https://www.neptunesystems.com/support/contact-support/

When I looked inside the device I thought it easily could which is what prompted my question to the community. You're correct in that it should not, but Simon points out it absolutely does.

Neptune should make this information publicly available or design and size their product so that it does not. Their forums aren't a beacon of hope. I will contact their support for more information. Thanks.

 

[DangerDave]

I use the flow sensors, and expect that it will create some drag, but I don’t think it’s anything major. Just make sure you use properly sized sensors.

 

[Johnseye]

I use the flow sensors, and expect that it will create some drag, but I don’t think it’s anything major. Just make sure you use properly sized sensors.

Yea it's really 1" or 2" for PVC. Not much of an option for sizing, like small or large, but I could use reducers on the 2". I bought the 1" for my manifold only to be surprised it only gets 325gph of flow. Now I want to make sure it gets as much flow through it as possible.

 

[ca1ore]

As example ….. intitially I used a 1" sensor on my main return (which was 1" at the time). Subsequently I replaced it with the 2" model (with the appropriate bushings) and got 50 gph more flow. Now that I use 1 1/2" pvc on the return the 2" is the only option.

 

[Johnseye]

As example ….. intitially I used a 1" sensor on my main return (which was 1" at the time). Subsequently I replaced it with the 2" model (with the appropriate bushings) and got 50 gph more flow. Now that I use 1 1/2" pvc on the return the 2" is the only option.

So it reduced it by 50gph. That's a big deal IMO and good to know, thanks Simon.

 

[SuncrestReef]

So it reduced it by 50gph. That's a big deal IMO and good to know, thanks Simon.

It’s not accurate to say the flow sensor alone reduced it by 50 gph. He stated he also changed the plumbing from 1” to 1.5”. Both of these changes made an impact.

 

[Johnseye]

It’s not accurate to say the flow sensor alone reduced it by 50 gph. He stated he also changed the plumbing from 1” to 1.5”. Both of these changes made an impact.

Good catch, that additional 1/2" in the return plumbing would absolutely have an effect. @ca1ore is this accurate?

 

[SuncrestReef]

The only way to really know the impact of the flow sensor is to time how long it takes the pump to fill a bucket, then add the flow sensor and test it again.

 

[Dr. Reef Verified Sponsor]

There will be a drag and naturally some flow will be lost due to the sensor.
How much? I think it wouldn't make much of a difference.
Like stated above, a little bucket to fill with and without sensor will give you a much clearer picture.
If I was to put a number on it, I would say a bucket test with flow sensor will be maybe reduced by 5 gph.

 

[ca1ore]

It’s not accurate to say the flow sensor alone reduced it by 50 gph.

Yes it is. Perhaps not written clearly or not understood …. Maybe this helps.

1. 1" plumbing and 1" flow sensor - nominally 900 gph
2. 1" plumbing and 2" flow sensor - nominally 950 gph
3. 1 1/2" plumbing and 2" flow sensor - nominally 1,250 gph

In case 1 versus case 2, the only thing changed was the flow sensor. Certainly these things have a level of inherent error, so the measurement of 900 versus 950 may be more, or less. Larger diameter plumbing makes a huge difference to flow, but the sensor does cost you gph. Maybe 50 is a big deal, maybe it's not. In my case, because I'm pumping up from a basement sump, every gph is important.

 

[ca1ore]

Good catch, that additional 1/2" in the return plumbing would absolutely have an effect. @ca1ore is this accurate?

Although it is true that larger diameter pipe makes a big difference to flow, the 50 gph difference I noted was with 1' piping in both cases (though two different sensors with inherent measurement error); otherwise the comparison would be invalid. You may find the difference to be more, or less, depending upon the kind of pump you are using and the exisitng head pressure.

 

[vangvace]

The impeller will cause a small loss in flow as will it getting dirty over time, just like pump blades. The bucket test and double checking your calculations for what the flow should be going through the manifold.

 

[DeputyDog95]

So how do you guys do the bucket test?

You can't really put a bucket in your tank where the water is returning, so how do you do it?