throttling back return pump

[tgriffin]

I might be misunderstanding this but a return pump can be throttled back by a valve of some sort without any negative effects. Correct???

I got a return pump based on the fact that I would eventually run several things through a manifold. In starting this system soon I might not have all the things that I was planning on running at first which could possibly leave me with too much flow for my overflow.

If I throttled this back with a valve would I be putting the pump under too much stress?

Thanks

 

[grouper therapy]

No.

Edit: What type of pump is it?

 

[ichthyoid]

We beat this up pretty well yesterday-

 

[tgriffin]

grouper therapy;614487 wrote: No.

Edit: What type of pump is it?

Blue Line 40 HD

Edit:

ichthyoid;614490 wrote: We beat this up pretty well yesterday-

http://www.atlantareefclub.org/forums/showthread.php?t=53629">http://www.atlantareefclub.org/forums/showthread.php?t=53629</a>[/QUOTE]

Thanks for the link.

I wasn't on the forums much yesterday. For some reason when I do a search on a topic I hardly get any returns, if any.

Maybe I should learn how to research better:).

I'll read through it

 

[rbredding]

I don't think the BL pumps recommend valving down the output (no pump recommends restricting input in any manner)...


the only pump that I've seen that says (YOU CAN DO IT) is the Sequence/Reeflo external pumps..

but there's not much difference in valving down a pump, or increasing head pressure (the pump is stupid, it doesn't know the difference)

 

[tgriffin]

Well, IF I throttled it back it wouldn't be much. The pump doesn't put out a whole lot as it is. Just trying to plan and get ready for setting this baby up!!!

 

[smoothie]

PM MRC. They will happily let you know and may be able to give ya specs on those pumps.

 

[grouper therapy]

Rbredding;614497 wrote: I don't think the BL pumps recommend valving down the output (no pump recommends restricting input in any manner)...


<u>the only pump that I've seen that says (YOU CAN DO IT) is the Sequence/Reeflo external pumps..
</em></u>
but there's not much difference in valving down a pump, or increasing head pressure (the pump is stupid, it doesn't know the difference)

<u> ONLY IF THE OUTPUT IS REDUCED ALSO!!!!!!</em></u>

 

[tgriffin]

While we are on the subject... Can someone give me a formula or something that I can figure out what a 90 or elbow will reduce flow?

So if I have plumbing that has say 5 elbows on it how much head or reduction in flow will I have lost

Thanks

 

[grouper therapy]

All centrifugal type pumps regardless of the driving mechanism have a sweet spot in the performance curve if you will where the impeller operates at a speed that it was designed for.. Usually it is somewhere in the larger middle of the curve. At this point the shaft on some and the magdrive on others runs the smoothest with less wobble of the shaft and impeller resulting in longer seal life and generally quieter operation.

Edit:

tgriffin;614515 wrote: While we are on the subject... Can someone give me a formula or something that I can figure out what a 90 or elbow will reduce flow?

So if I have plumbing that has say 5 elbows on it how much head or reduction in flow will I have lost

Thanks

Depends on the size of the pipe.

Edit:

Rbredding;614497 wrote: I don't think the BL pumps recommend valving down the output (no pump recommends restricting input in any manner)...


the only pump that I've seen that says (YOU CAN DO IT) is the Sequence/Reeflo external pumps..

but there's not much difference in valving down a pump, or increasing head pressure (the pump is stupid, it doesn't know the difference)

There is absolutely no difference.

 

[cr500_af]

tgriffin;614515 wrote: While we are on the subject... Can someone give me a formula or something that I can figure out what a 90 or elbow will reduce flow?

So if I have plumbing that has say 5 elbows on it how much head or reduction in flow will I have lost

Thanks

Google "pump head loss calculator". Look for links that are on reef sites out of the results.

There are a few out there, but not every one has every brand of pump. You can specify everything about your plumbing, and it will return your GPH in your exact configuration. While I'm sure it isn't 100% perfect, it will get you very close.

 

[tgriffin]

cr500_af;614524 wrote: Google "pump head loss calculator". Look for links that are on reef sites out of the results.

There are a few out there, but not every one has every brand of pump. You can specify everything about your plumbing, and it will return your GPH in your exact configuration. While I'm sure it isn't 100% perfect, it will get you very close.

Will do. Thanks for the recommendation. I'm in NYC till tomorrow and I am getting horrible internet service (go figure!!) and am having to use my blcackberry. It might be tomorrow when I get back home before I can check it out.

Thx again!

 

[ichthyoid]

tgriffin;614515 wrote: While we are on the subject... Can someone give me a formula or something that I can figure out what a 90 or elbow will reduce flow?

So if I have plumbing that has say 5 elbows on it how much head or reduction in flow will I have lost

Thanks

My mentor used to say to use 6% reduction per 90 degree fitting (under practical conditions).

Then, there is also a very complex solution to this question...

FWIW- the man had a PhD in Aeronautical Engineering and was a fluid dynamics whiz!

 

[grouper therapy]

For a Blueline HD40

1 inch diameter 90 elbow will result in an additional .25 feet of head .
Using a 3/4" 90 elbow would result in approximately .42 feet of head. The biggest difference will be the 6 feet of vertical lift with either 3/4" or 1" pipe the 3/4" increase your head from around 6' to 8'.

Edit:

ichthyoid;614536 wrote: My mentor used to say to use 6% reduction per 90 degree fitting (under practical conditions).

Then, there is also a very complex solution to this question...

FWIW- the man had a PhD in Aeronautical Engineering and was a fluid dynamics whiz!

I would tell you your mentor was wrong but I fear this may happen!!j/k
http://www.youtube.com/watch?v=_ZpDnXYIFjo&feature=related

Edit:

ichthyoid;614536 wrote: My mentor used to say to use 6% reduction per 90 degree fitting (under practical conditions).

Then, there is also a very complex solution to this question...

FWIW- the man had a PhD in Aeronautical Engineering and was a fluid dynamics whiz!

I would tell you your mentor was wrong but I fear this may happen!!j/k
<div class="gc_ifarem_title">YouTube - Conflict Resolution - The Waterboy</div>

Edit:

ichthyoid;614536 wrote: My mentor used to say to use 6% reduction per 90 degree fitting (under practical conditions).

Then, there is also a very complex solution to this question...

FWIW- the man had a PhD in Aeronautical Engineering and was a fluid dynamics whiz!

I would tell you your mentor was wrong but I fear this may happen!!j/k
<div class="gc_ifarem_title">YouTube - Conflict Resolution - The Waterboy</div>

Edit: Sorry for the triple post

Edit: why can't I edit?

Edit:

For a Blueline HD40

1 inch diameter 90 elbow will result in an additional .25 feet of head .
Using a 3/4" 90 elbow would result in approximately .42 feet of head. The biggest difference will be the 6 feet of vertical lift with either 3/4" or 1" pipe the 3/4" increase your head from around 6' to 8'.