D5 Pump Not Strong Enough?

[turok_t]

Hi everyone, I just got a Singularity Computers Protium D5 reservoir and an alphacool VP655 D5 PWM pump. I?m testing them out of my system to make sure that the pump works fine before installing it in my build. Water travels from the radiator up to the inlet of the pump/reservoir and then it leaves the pump into the green tube (testing only) going back into the radiator. My question is this, there is a huge air bubble in the green tube close to the outlet of the pump and it looks like the pump isn?t able to pump the water strong enough causing the massive air bubble. It looks like water is just trickling down the green tube. Is this normal? I made a video and posted it in the link below.

 

At first, I thought this might be caused by the 90 degree inlet bend restricting the water flow into the pump. But then again, the pump is gravity fed by the reservoir so there is plenty of water feeding the pump and this shouldn?t be a feeding/intake problem.

 

I tried using a different D5 pump (Laing D5T Vario) and I get the same result. I also tried a different PSU (EVGA 850W) and get the same result.

So is that massive air bubble normal when water is leaving the pump? Or do I have to wait for it to naturally bleed itself out of the loop? I?m worried that my pump isn?t strong enough, but then again, I know D5 pumps can push through a lot.

 

Any comments/suggestions would be helpful, thanks.

 

 

https://youtu.be/HQ9Lx82aqIw

[RollinLower]

your D5 should be able to push through this with ease. are you sure there is no air in the pump itself? these pumps need to be fully submerged to function properly.

[For Science!]

Make sure inlet/outlet is correct? the D5 should have absolutely no problem with this

[turok_t]

Yes, im 100% sure that the inlet and outlet (there is only 1) are correct. How do I ensure there is no air in the pump itself? The pump is attached below the reservoir which is being fed by a column of water by gravity. Here is a diagram below, "C" is my inlet port and "E" is my outlet port.

 

[turok_t]

One thing that just came to my mind. My radiator is higher than my reservoir, so im guessing as i fill in my reservoir, the radiator will be filled up to the same level as well. However, once i fill my reservoir to the max, there is still a gap at the top of my radiator. Will this top section be filled with water too as the pump pushes the water in? or will the water level of the radiator always match the reservoir? The reason why im asking is because i want the radiator to be completely full even though my reservoir is lower.

[Blai5e]

15 minutes ago, turok_t said:

One thing that just came to my mind. My radiator is higher than my reservoir, so im guessing as i fill in my reservoir, the radiator will be filled up to the same level as well. However, once i fill my reservoir to the max, there is still a gap at the top of my radiator. Will this top section be filled with water too as the pump pushes the water in? or will the water level of the radiator always match the reservoir? The reason why im asking is because i want the radiator to be completely full even though my reservoir is lower.

I'm using the same pump (Protium D5), make sure you disconnect the PWM cable. I was having the same problem (and I used a separate PSU when filling my rig) whereby I wasn't get enough flow (big air bubble wouldn't clear from my GPU waterblock). Even though I had the system powered off, the PWM sense wire was plugged into my Commander Pro. Soon as it was unplugged... 100% pump speed.

[turok_t]

11 minutes ago, Blai5e said:

I'm using the same pump (Protium D5), make sure you disconnect the PWM cable. I was having the same problem (and I used a separate PSU when filling my rig) whereby I wasn't get enough flow (big air bubble wouldn't clear from my GPU waterblock). Even though I had the system powered off, the PWM sense wire was plugged into my Commander Pro. Soon as it was unplugged... 100% pump speed.

If you read my posts above, I did not have my PWM connected, the pump is only connected by molex

[For Science!]

7 hours ago, turok_t said:

One thing that just came to my mind. My radiator is higher than my reservoir, so im guessing as i fill in my reservoir, the radiator will be filled up to the same level as well. However, once i fill my reservoir to the max, there is still a gap at the top of my radiator. Will this top section be filled with water too as the pump pushes the water in? or will the water level of the radiator always match the reservoir? The reason why im asking is because i want the radiator to be completely full even though my reservoir is lower.

this is not a concern. The pump is typically in a very low place in the loop, and it still pushes out almost all the air without assistance.

[turok_t]

Alright, I think I fixed it after some testing today.

Here is a video of the pump spinning, notice how its spinning quite fast and generating a lot of air bubbles? The air bubbles are then fed back out from the pump into the water loop. Also, notice how loud the pump is? With all the pumps I used in the past, it never sounded this loud.

 

https://youtu.be/ojIQlHWkOr4

 

After connecting it to a separate computer, this is how my pump sound like now. It’s completely inaudible (the background noise you hear is from the computer at the back). There are minimal air bubbles in the reservoir and inlet and outlet tubes from the pump. This is how quiet I am used to with my previous pumps. When I went into the BIOS, my pump was spinning at 1800RPM (Normal Speed). If I increased the pump speed to 4787RPM (Full Speed), I can replicate the loudness in the first video which sounds like a turbine. I also tried used a different inlet (top of my multi-port cap) on my reservoir and the water seems to be flowing well and not trickling or splashing back in.

 

https://youtu.be/lYzx9GVfms0

 

So all in all, it was indeed the pump speed/RPM. After modulating its speed, there are less air bubbles, less turbulence and the pump is much quiet now. I still did do a lot of tilting and rotating to bleed out the air bubbles as much as possible, but this looks and sounds much better than before. I’m more confident with my pump now and will reinstall it back in my system.

[turok_t]

Hi everyone, here is an update on my build. Pump and reservoir has been installed back into my rig and I’m just leak testing everything. So far, there are no leaks, however, I’m wondering if my pump flow is being restricted. As you can see from the picture below, I have a sharp 90 degree angle as the pump outlet, and sharp 90 degree angle as the pump inlet. I’ve seen other builds with these angled fittings, so I thought it would be okay. Would the 90 degrees outlet restrict the water coming out of the pump? The reason why im asking is because I have a flow meter right after the water leaves the pump and it is showing 10 revs/second and 0.4L/min which is really low, especially when the pump is on full speed at 4700 RPM. My flow meter works perfectly as I tested it out before on my other rigs. On my other rigs, when my D5 Vario was on setting 3-4, it would show 40 rev/sec and 1.8L/min. But now on my D5 PWM pump it is showing much less flow at max speed. I also included a video of this at the bottom too, along with my entire water loop. I have a CPU and GPU waterblock and two 360 rad.

 

Here is the video:
https://youtu.be/otqEArfF0vI
 

[For Science!]

The angled fittings are fine, i wouldnt put too much trust or value in the flow rate. It makes minimal impact to cooling performqnce anyway

[thrasher_565]

12 hours ago, For Science! said:

The angled fittings are fine, i wouldnt put too much trust or value in the flow rate. It makes minimal impact to cooling performqnce anyway

well depends on if you want the best of the best. having strate fittings is cheaper and is free performance every 90 you have decreases the flow rate.  but this pc is clearly for looks. the 90 degree tube bends are fine but the 90 degree fittings are not for max performance

[turok_t]

Thanks for all your comments guys! anyways, I fixed the issue. The flow meter is much more accurate now and increasing the pump RPM doesn't create bubbles from the impeller. All the air bubbles are gone and the pump is inaudible even at high RPMs.

[fonzz1e]

23 hours ago, turok_t said:

Thanks for all your comments guys! anyways, I fixed the issue. The flow meter is much more accurate now and increasing the pump RPM doesn't create bubbles from the impeller. All the air bubbles are gone and the pump is inaudible even at high RPMs.

good job

was it caused by air being in the loop/pump?

[turok_t]

The flow meter has a turning wheel that calculates revolutions/second and liter/minute. I think the the air bubbles were blocking the water flow affecting the turning wheel, and therefore, it displayed a reading that was low. After a lot of tilting, changing the pump speed to get rid of the bubbles, the readings gradually increased. Before, turning the pump even past 50% of its speed caused a lot of crackling from the air being generated by the impeller. But now, even at 75% speed, there isn't any noise.