Idea to reduce head height, alternative to 90° elbow

[TheFishTeen]

Although the ReeFlo Hammerhead is a very strong pump, it does not score best in high pressure situations. I figure I have about 11' feet vertical head and ~17' feet horizontal. I called up ReeFlo, and they said not to figure in the horizontal distance into the total head pressure. So I have 11' feet of head (apparently).

Now with that, I do have 4, 90° elbows needed to get to the tank.

One member here posted that a 90° elbow is the equivalent of 2 feet of head.

So with that fact in place, I have 19 feet of head pressure.

Here's my idea. I have read that Flex PVC is not pressure rated - but then again I have seen countless threads where people use flex pvc on strong pumps.

So, IF flex PVC can be used on the return line of the ReeFlo Hammerhead, I had the idea to replace all four 90° elbows with a graduated bend with Flex PVC, in hopes to greatly reduce the friction against the pump, thus reducing head loss.

So my question is:

Will this method reduce head loss?

Heres what I mean:

On the left is what one turn with a 90° elbow would be like. One the right, is the alternative. I am still making a full turn, but it is dragged out much longer.

Here is the Head to Flow chart via the manufacturer.

 

[Breadman03]

What about using PEX? The stuff is fantastic in home plumbing. I know it is available in 3/4", but am unsure about larger. I'm going to go look now.

 

[r-balljunkie]

yes, using spaflex woudl reduce the friction losses verses a 90, but you'd be hard pressed to get that kind of bend out of spaflex.
end of the day, you do not want to put any stress on the bulkheads. could cause your glass to crack.
forcing the spaflex may transfer stress.

2x 45 deg elbows is a good alternative to make a jog of 90 degrees.

i wouldnt put too much merit in pressure ratings listed. it will flow, but perhaps at a derate to gph.

http://www.engineeringtoolbox.com/pvc-pipes-equivalent-length-fittings-d_801.html

 

[TheFishTeen]

What about using PEX? The stuff is fantastic in home plumbing. I know it is available in 3/4", but am unsure about larger. I'm going to go look now.

You bring up PEX in reply to what? If Flex PVC handles the pressure?

 

[Breadman03]

http://www.pexinfo.com/ says it is commonly available up to 1", but that it can be found up to 2".

http://www.pex-tubing.com/technical-specifications-of-pex-tubing lists the technical specs up to 1". 160psi rating at 74 degrees sounds good to me.

Feel free to school me up.

 

[TheFishTeen]

yes, using spaflex woudl reduce the friction losses verses a 90, but you'd be hard pressed to get that kind of bend out of spaflex.
end of the day, you do not want to put any stress on the bulkheads. could cause your glass to crack.
forcing the spaflex may transfer stress.

2x 45 deg elbows is a good alternative to make a jog of 90 degrees.

i wouldnt put too much merit in pressure ratings listed. it will flow, but perhaps at a derate to gph.

http://www.engineeringtoolbox.com/pvc-pipes-equivalent-length-fittings-d_801.html

Not sure really why you bring up the glass and bulkhead breaking. One end is coming off the pump and the other is going into an Oceans Motions unit. Plus, all the piping is going to be supported with clamps.

On the 2 x 45°, from what Ive seen it is the same thing as a 90° elbow.

 

[TheFishTeen]

http://www.pexinfo.com/ says it is commonly available up to 1", but that it can be found up to 2".

http://www.pex-tubing.com/technical-specifications-of-pex-tubing lists the technical specs up to 1". 160psi rating at 74 degrees sounds good to me.

Feel free to school me up.

Found this: http://www.pexsupply.com/Wirsbo-Uponor-F1022000-2-AQUAPEX-300-ft-coil-8843000-p

Max PSI: 160 psi
Max Temp (F): 200°F

But is it aquarium safe?

 

[Breadman03]

You bring up PEX in reply to what? If Flex PVC handles the pressure?

As a method of tailoring the radius to whatever is desired, and I know it has good pressure capacity. It served me well in my house and I am considering using it when I build a sump, so I mentioned it.

I have also used connectors that go from PEX to copper or PVC with good results, so figure it may be able to be. Corporates into a PCV design fairly easily.

 

[Breadman03]

Found this: http://www.pexsupply.com/Wirsbo-Uponor-F1022000-2-AQUAPEX-300-ft-coil-8843000-p

Max PSI: 160 psi
Max Temp (F): 200°F

But is it aquarium safe?

http://www.nsf.org/business/plastics_piping/faq_pex.asp?program=PlasticsPipSysCom

Since PVC for residential use has to be NSF certified (I assume) for use in potable water supply and PEX also has to, I think it is likely it could be used. This page lists some of the VOC's that are tested for.

This site has more information that you more experienced folks may find useful.
http://www.findmeaninspector.com/?D=94

 

[CHSUB]

you will reduce head some and flex pvc is fine...i used it before without any issues. i think a 90 adds 1 foot of head not 2!

 

[TheFishTeen]

i wouldnt put too much merit in pressure ratings listed. it will flow, but perhaps at a derate to gph.

http://www.engineeringtoolbox.com/pvc-pipes-equivalent-length-fittings-d_801.html

Holy cow! How is this chart correct? 8.6 feet equivalent of straight pipe in a 2" 90° elbow? I think I'm missing something here.

 

[CHSUB]

those are right, i believe; a 90 is 1 foot of head or 16 feet horizontal for 1" pipe...

 

[James77]

That 90*=1 foot of head is nonsense IME. I have had setups with enough 90* elbows to shut a pump down if that was the case.

Use the widest pipe possible makes far more differecne

 

[Dashiki]

Have you tried to find sched40 sweep 90's. They have them at my hd. It looks like the sweep you are trying to do with the spaflex

 

[inaspin]

Well I don't post much because I don't know much about tank keeping yet I do however know alot about plumbing I have pipe worked on everything from a Nuke sub to an outhouse in NC. From what I have gathered in your post you want the least head pressure that you can get. Pressure is created by elevation and pipe size reduction for the most part. The type of fittings you use in getting have very little to do with it , so using 1/4,1/8 or 1/16 bends don't worry about that part to much. On the question about the type of pressure rated pipe is not a big deal either unless you plan on having a shut off valve in the line that you want to use with out turning the pump off or you are going to reduce pipe size towards the end. What I mean by this is the only small amount of pressure you have is in fact the head pressure when you have an open end pipe. I hope this helps you out I have tried to give you the best information based on my experience. I am not saying I know it all I do not but, I think what I stated here is fact. I am only trying to help not disagree with anyone, I hope its not took that way. Good luck with your project.

 

[Haffs09]

What is your target flow rate to your display tank?

 

[TheFishTeen]

Thank you all for your contributions - but my initial question has still gone unanswered.

Will replacing a standard 90° Elbow with an arc built with Flex PVC or a product alike in which a 90° turn is extended over a large radius (example: 20") reduce head loss?

 

[TheFishTeen]

Have you tried to find sched40 sweep 90's. They have them at my hd. It looks like the sweep you are trying to do with the spaflex

A sweep 90 is basically what Im trying to accomplish, but larger. People recommend sweep 90s on return pumps because the 90 degree turn isn't as intense, and longer, consequently reducing pressure against the pump.

So by using Flex PVC, i am creating a large sweep to further the reduction in head loss.

Well I don't post much because I don't know much about tank keeping yet I do however know alot about plumbing I have pipe worked on everything from a Nuke sub to an outhouse in NC. From what I have gathered in your post you want the least head pressure that you can get. Pressure is created by elevation and pipe size reduction for the most part. The type of fittings you use in getting have very little to do with it , so using 1/4,1/8 or 1/16 bends don't worry about that part to much. On the question about the type of pressure rated pipe is not a big deal either unless you plan on having a shut off valve in the line that you want to use with out turning the pump off or you are going to reduce pipe size towards the end. What I mean by this is the only small amount of pressure you have is in fact the head pressure when you have an open end pipe. I hope this helps you out I have tried to give you the best information based on my experience. I am not saying I know it all I do not but, I think what I stated here is fact. I am only trying to help not disagree with anyone, I hope its not took that way. Good luck with your project.

Sorry, i don't exactly understand.

What is your target flow rate to your display tank?

As much as possible. :fish1:

 

[Haffs09]

The answer to your question is yes. But, I don't think it will make a significant difference. Flex PVC will be fine. I use it off my main pump and a hammerhead isn't a high pressure pump. At its shutoff head pressure, it is only outputs 10psi. If it runs dry, you run the risk of overheating it and it could generate very hot water or steam, and then you may be in trouble. I had this happen to a pool pump and the 2" vinyl supply hose swelled to 4" in diameter before my neighbor killed the power!

I'm sure the flow to your tank is limited by the rating of your overflow, so that's why I asked for your desired flow rate.

I'm using a hammerhead to run my system. It supplies a manifold that runs to a protein skimmer, 75gal and my display tank. I have approximately 14' of vertical head to my display tank. Once there, it goes to a manifold that can supply 5 returns. There are many tees, valves, 90s and 45s to get to the DT. The supply line is 1.5" and it gets reduced to 1" at the DT and then down to 3/4" for loc line fittings. Here are my observations:
- While supplying a VS-36 LifeReef skimmer, a 75gal tank and all 5 returns (valved back) I was getting ~1500gph to the display tank.
- When only supplying the DT with all 5 returns 100% open, I get 1500-1800gph (I can't remember exactly what it was).
- I'm currently supplying only 2 returns to the DT 100% open, and the 75gal. I getting ~1200gph to the DT.

I'm using a kill-a-watt meter to tell my the wattage the pump runs at and then plot that along its flow curve to determine gph. I hope loc-line makes a 1" version, so that I don't need to reduce it at my return bulkheads. I think going 1" on my returns will increase the flow by a couple hundred gph.

Check out posts 61-64 of my build thread for pics, so you'll get a better idea of my layout: (http://reefcentral.com/forums/showthread.php?t=1831347&page=3

 

[TheFishTeen]

The answer to your question is yes. But, I don't think it will make a significant difference. Flex PVC will be fine. I use it off my main pump and a hammerhead isn't a high pressure pump. At its shutoff head pressure, it is only outputs 10psi.

Any difference, is a significant difference in my case. Keep in mind: my goal is to get the most flow I could possibly get.

If it runs dry, you run the risk of overheating it and it could generate very hot water or steam, and then you may be in trouble. I had this happen to a pool pump and the 2" vinyl supply hose swelled to 4" in diameter before my neighbor killed the power!

I am aware of the dangers of the pump running dry. I will be using a liquid level sensor dedicated for the pump to shut it off it the event the sump water lever is too low.

I'm sure the flow to your tank is limited by the rating of your overflow, so that's why I asked for your desired flow rate.

No worries here, this is a custom tank and I will have the builder drill an appropriate overflow to handle the Hammerhead.

I'm using a hammerhead to run my system. It supplies a manifold that runs to a protein skimmer, 75gal and my display tank. I have approximately 14' of vertical head to my display tank. Once there, it goes to a manifold that can supply 5 returns. There are many tees, valves, 90s and 45s to get to the DT. The supply line is 1.5" and it gets reduced to 1" at the DT and then down to 3/4" for loc line fittings. Here are my observations:
- While supplying a VS-36 LifeReef skimmer, a 75gal tank and all 5 returns (valved back) I was getting ~1500gph to the display tank.
- When only supplying the DT with all 5 returns 100% open, I get 1500-1800gph (I can't remember exactly what it was).
- I'm currently supplying only 2 returns to the DT 100% open, and the 75gal. I getting ~1200gph to the DT.

I'm using a kill-a-watt meter to tell my the wattage the pump runs at and then plot that along its flow curve to determine gph. I hope loc-line makes a 1" version, so that I don't need to reduce it at my return bulkheads. I think going 1" on my returns will increase the flow by a couple hundred gph.

Check out posts 61-64 of my build thread for pics, so you'll get a better idea of my layout: (http://reefcentral.com/forums/showthread.php?t=1831347&page=3

I have been following your build but never got the chance to comment on it. So far you have done an excellent job.

Thank you for taking the time to answer my question.