Sorry about that Luke. It was great seeing you again though. Russ don't worry, the testing will begin soon....
I did a quick test today after inputing all of the pipe specifications and distances for the transducers, but I think I need to change things up because there is a lot of fluctuation in both the pressure and flow rate. I have 3' piece of pipe inside the tank but I think now that I am home I will make a 10' long suction pipe to clean up that water more for smoother flow. I will also move the pressure gauge to a flat section of piped hope that cleans up the pressure range. It kept fluctuating between 0.3 feet of H2O and 0.9 feet of H20 at full blast from the A2-1/3-63-C pump I used. Hopefully I can clean that up a little for more accurate results.
Zac Penn.... Please sign-up for our MAILING LIST HERE904-294-2231
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Move pressure gauge closer to pump. Perhaps a baffle in the tank to diffuse currents?
I would move the pressure gauge closer to the pump but I don't want it to be in the way of swapping out different pumps. I guess now that I am back home I don't need the station to be as user friendly when it comes to swapping pumps but I still don't want to drill and retap multiple pipes when switching pumps.
Zac Penn.... Please sign-up for our MAILING LIST HERE904-294-2231
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It is best the reducer and/or any fitting is at least 5 pipe diameters on both the suction and discharge lines away from the pump. You achieve the best performance of the impeller with laminar flow, ... although that probably doesn't represent but 1% of the actual installations!
I also believe, the same pump with and without the leaf basket will probably have significant different curves too. All good stuff if you find the time to check. Thanks for this info.
Zac, maybe a DIY laminar flow baffle will help sort out any unwanted turbulence.
They aren't difficult to make, but will add a bit of head.
Since the pump intake pipe is straight and the reducer is large to small losses due to turbulence will be minimal. The biggest killers are direction change fittings such as 90s and 45s directly on a pump. Not a perfect setup but probably accurate enough for comparisons. I would try a baffle inside the tank first. It can something very simple just placed into the tank to break up and distribute flow.
Zac mentioned .3 to .9 Ft head wide open. At very low head some pumps this might be a normal characteristic? Does the flow stabilize as head pressure is increased a little?
Last edited by BWG; 03-13-2018 at 10:50 PM.
I will play around with some different setups on the suction side to see if I can clean up the water swirling inside the pump.
On the pressure side the head variation remains relatively constant as i increasingly resistance. Wide open there is roughly a .6 feet variance, and at 10' there may be a .5 variance so not much improvement. 6" of head doesn't seem like much, but on the low head style pumps that can be a huge restriction and it will really muddy the waters if I can't reduce that fluctuation. On a standard koi pond pump w/ a shutoff head of 25' that 6" won't really matter much in our data collection.
Zac Penn.... Please sign-up for our MAILING LIST HERE904-294-2231
Zac@DeepwaterKoi.com
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Moving the pressure gauge out of the 90 fitting and closer to the pump should be a more stable and accurate head reading since the 90 even though it is large contributes to turbulence and head pressure loss. The gauge is currently downstream and after the 90. If the flow meter on the intake fluctuates at various head pressures then a tank baffle should help.
Some pumps don't list full flow at near zero head. Maybe it's normal for some to fluxuate at these conditions?
Last edited by BWG; 03-14-2018 at 10:23 AM.
I have finally started the actual testing station thread in my marketplace....
https://www.koiphen.com/forums/showth...esting-Station
Zac Penn.... Please sign-up for our MAILING LIST HERE904-294-2231
Zac@DeepwaterKoi.com
www.DeepwaterKoi.com
I don't know much about these types of pumps but I do know in submersible well pumps if they are designed for deeper wells and put in a shallow well or one with a high water level they will wear out much faster due to "upthrust" which is basically there isn't enough back pressure to hold down the impellers in the pump and they will start to float and even the insides of the motor will try move upwards. The pump curves will start at a certain head like the curve you pictured. I'm sure it's not exactly the same thing but maybe something similar.