GPH Physics Question...

[AngeloM3]

OK.... I want to plumb a return manifold. This will NOT be on a closed loop. I have a Mag 9.5, the Mag has to pump 5ft up... then the manifold with run horizontal at a total of 4ft (3ft of it will be on the right side of the "T" from the return and 1ft of it will be on the left side of the "T"). It will have 4x 45degree outputs (3 on the right side of the "T" and 1 on the left side of the "T")

The Mag 9.5 at 5ft is rated at 750gph. With this manifold will the Mag still put out 750gph or does the gph get reduced?

I understand that the outputs from the manifold might not be all that strong but it will give me good random flow with 4 powerheads I'll run on a wavemaker.

 

[dots]

http://www.advancedaquarist.com/issues/jan2003/featurejp.htm

please note equation #2 for why your outputs may not be that "strong" but instead your equation will look like Qtotal=Q1+Q2+Q3+Q4; with Q=A*V. In other words working backwards: (flow outlet1+flow outlet2+flow outet3+flow outlet4)+flow loss due to friction of the system from the pump=pump flow at pump (0').

To find your mass flow rate (Q) at the exits you need to find the losses due to friction and subtract them from the flow rate at the pump.

There is a calculator at the end, but try it by hand to truly appreciate the work that went into creating it by calculating Eqn #3.

 

[AngeloM3]

<a href=showthread.php?s=&postid=9617877#post9617877 target=_blank>Originally posted</a> by dots
http://www.advancedaquarist.com/issues/jan2003/featurejp.htm

please note equation #2 for why your outputs may not be that "strong" but instead your equation will look like Qtotal=Q1+Q2+Q3+Q4; with Q=A*V. In other words working backwards: (flow outlet1+flow outlet2+flow outet3+flow outlet4)+flow loss due to friction of the system from the pump=pump flow at pump (0').

Huh? I'm no math expert... I dont wanna know the output at each 45. I want to know if the Mag 9.5 gph reduces or not with manifolds when its not on a closed loop.

Sorry I read that page and had no clue how to figure that out. I'll accept layman's explanations

 

[dots]

(flow in)-(friction loss due to bends, pipe diameter,vertical rises(gravity), and type of fluid being pushed) =flow out

(flow=gallon per hour=Q=flow area*velocity of fluid)

So gallon per hour is based on the area of the pipe and how fast the fluid is going..........if the area increases, the velocity decreases.........thats why a Seio or Tunze FLOWs the same as a standard PH, but has less FORCE(velocity).

Your Mag will loose some of its gph because of friction loss from water being pushed from point A to point B in the pipe. How much depends on the design based on: #bends, pipe diameter, vertical rises/gravity, and the Reynolds number (flow inside the pipe), type of fluid being pushed.

All pumps will loose gph out the other end every time they pump water through a pipe system.....how much is the key in a good design and an engineer trys to minimize this loss.

So yes, you will loose gph regardless if you use the mag for the return pump or the CL pump.....how much exactly for each and which one less than the other needs to be calculated by that Excel calculator on the bottom of the link and comparing the two designs for the one that is the most efficient.

So your going to loose some gph, how much depends on how many bends and the diameter of your pipe and how high up you have to pump the water up. Find the design that robs the least from you.

 

[AngeloM3]

Alright... thanks for the idiot explanation!
I didnt think the excel was a "calculator".... I'll definatly try it out though.


Thanks again for the link!

 

[silverwolf72]

Just use the calculator on the main page But yeah your going to loose a bit of flow.

 

[BeanAnimal]

<a href=showthread.php?s=&postid=9624140#post9624140 target=_blank>Originally posted</a> by AngeloM3
Alright... thanks for the idiot explanation!
I didnt think the excel was a "calculator".... I'll definatly try it out though.


Thanks again for the link!

What exactly did you think it was? (being honest!)

A recent survey of secretarial AND managerial employees in OFFICE JOBS, where they used computers for their work during a MAJORITY of the day... showed that over 80% had no idea how to use excel for anything more than putting things in columns to organize them!!!! Most did use excel on a regular basis and were not aware that it had ANY mathemtical functionality! Many of the others were only aware that it could do "SUMS" by grouping items and clicking the "auto sum" button.

 

[Fish'InMN]

I'd be dead in the water (no puns intended) if I didn't know how to use and program Excel. But I'm not much of an office person anways...

Always insightful, Bean; thanks again.

Marty