Installing my new Sequence 750 pump

[miamicuse]

Looks like a LOT of elbows. Have you calculated your head pressure just in the plumbing? Have you thought about using flexible PVC? You could reduce your head a bunch I bet.

It is a lot of elbows, and a long run from pond to pump and back. I did some calculations on pipe length and fitting losses in a previous post (based on some assumed flow rates).

Since the majority of the pipe length will be buried, flexible PVC is not an option in Florida where we have so many flex PVC used in pools being damaged by subterrainean termites when buried below grade.

 

[miamicuse]

WE ALSO MENTIONED USING SWEEP elbows AND DRAIN BUT HE HAS OPTED TO USE THE 90 DEGREE ELBOWS

That's true. I just have a problem using products that is not listed for the application. I know that the drain elbows will probably, and most likely work, but I don't like the much shallower hub depth compared to the pressure elbows in terms of making a solid interference fit for solvent welding.

If the work is exposed so that I can keep an eye on it, it may be a different story. But most of the run will be buried below grade, worse yet, my wife wants to put brick pavers over it, so not only it will be covered, it will be covered then a compactor will be vibrating over it.

I have considered an alternative that will provide the sweeping curve that reduces friction loss and yet still using pressure fittings, and that is I can use regular SCH40 PVC pipes, and just heat bend my own elbows then use straight couplings. That's extra work but it is doable.

But when I did the calculations of the head loss of 22 pressure 90 elbows is 2.28' vs 22 drain elbows is 1.26', that's 1' of head over the 15'-25' that I am seeking, I don't think the difference is significant enough.

 

[GBBUDD]

a MILLION PONDS IN THE USA can't all be wrong Everyone uses drain pvc schedule 40

 

[miamicuse]

a MILLION PONDS IN THE USA can't all be wrong Everyone uses drain pvc schedule 40

In that case, I will probably be the one out of a million that is so lucky to have failure considering my luck.

Charlotte Pipe rated and tested their PVC drain fittings to 4.3PSI. I am new to ponds but I kind of go by my experience with swimming pools and spas. My pressure gauge on my pool plumbing shows around 20PSI so drain fittings will most likely blow apart. Everyone I know down here with a pool have pressure fittings for their pools, I don't think one could even pass the pool inspection if pool plumbing uses drain elbows. While a pond is mostly likely shallower with shorter pipe runs, to me it's still a risk not worth taking. My calculations showed the difference between the pressure elbows and drain elbows resulted in 1' of extra head loss, which wouldn't make the Sequence pump work anyway. If the difference was higher, like 4-5' of extra head loss, then I will heat bend PVC pipes into 90 elbows and use pressure couplings instead.

 

[combatwombat]

I think you're more likely to experience a pressure failure from the thinned out PVC wall that results from a 90º+ heat bend than from the shallower hub of a DWV fitting. And that's beside the point because liklihood of failure is ridiculously small in either case.

DWV is not rated/tested to 4.3 PSI. That # is irrelevant to us. That is what Charlotte recommends using for pre-inspection leak test in a waste plumbing application to account for most real-world waste plumbing applications. It is rated for 0 PSI.

And the fact that your pool system with reads 20 PSI does not mean that DWV plumbing would blow apart at 20. 1.5" Sch. 40 PVC is rated for something like 400 PSI. In any case, you've made your decision on what to use, and that's fine.

What pumps are you looking at now?

 

[miamicuse]

What pumps are you looking at now?

I am still searching. Right now I have a few on my list.

(1) Quiet Drive QD6050 can do 6100GPH max head 23' but I can't find a flow vs head curve.

Quiet Drive QD6050 Medium Pressure External Pump

Made by Sequence Pumps, the manufacturing LEADER in High-Efficiency, Premium Quality External Pond Pumps.The Quiet Drive Medium Pressure Series external pump offers energy efficiency and great performance for most water gardens. The motor is totally-enclosed, and fan-cooled for durability...

webbsonline.com

Technical sheet

https://webbsonline.com/media/ecom/prodpdf/Quiet-Drive-Manual.pdf

Apparently this is made by Sequence, and it does look very similar. I wonder why a different brand.

(2) EasyPro GV75S self priming integrated priming pot

EasyPro External Pump, Self-Priming 115 volt

If you're looking for a great quality external self-priming pond pump at an affordable price point, look no further! Perfect for ponds, waterfalls, filters and other water features. These high performance, medium head external pumps come complete made of 100% recyclable plastic. Noncorrosive...

webbsonline.com

Technical sheet:

https://webbsonline.com/media/ecom/prodpdf/SpecSheet-GV_S_SeriesMedHead.pdf

according to the curve the GV75S can do 3200GPH and push a 35' head.

(3) Anjon Manufacturing LandShark LS4600 or LS5500 self priming

Anjon LandShark External 4,600 GPH Pump

The Anjon Landshark High Efficiency External Water Pump is a self-priming heavy-duty external water pump that delivers outstanding reliability and performance. This unit is equipped with a low maintenance, self-lubricating direct drive motor. The hydraulically self-balancing impeller provides...

webbsonline.com

pump curve:

Anjon LandShark External 4,600 GPH Pump

The Anjon Landshark High Efficiency External Water Pump is a self-priming heavy-duty external water pump that delivers outstanding reliability and performance. This unit is equipped with a low maintenance, self-lubricating direct drive motor. The hydraulically self-balancing impeller provides...

webbsonline.com

at 3200GPH the LS4600 can do 18' head and the LS5500 can do 23' head

(4) PerformancePro Artesian 2 and they have multiple classes of external pumps, some are "high head" and some are "high flow".

The high flow 1/2HP pump:

PerformancePro 1/2 HP Artesian2 High Flow Pump 7,200 GPH

Artesian2 is the perfect choice for high efficiency and reliability combined with the convenience of self-priming. Molded of corrosion-resistant polypropylene. Artesian2 pumps are ideal for applications in which the pump is positioned above the water level. An easy-open Lexan lid provides ready...

webbsonline.com

The high head 1/2HP:

PerformancePro 1/2 HP Artesian2 High Head Pump 6,660 GPH

Artesian2 is the perfect choice for high efficiency and reliability combined with the convenience of self-priming. Molded of corrosion-resistant polypropylene. Artesian2 pumps are ideal for applications in which the pump is positioned above the water level. An easy-open Lexan lid provides ready...

webbsonline.com

It seems both can do what I need based on the curves alone, but I am a bit confused of their differences.

I haven't looked at submersibles yet, I feel like I need to give it some serious thoughts although I would prefer to keep the external pump setup.

 

[combatwombat]

(1) Quiet Drive QD6050 can do 6100GPH max head 23' but I can't find a flow vs head curve.

The curve is listed in increments on the product page for each size pump:

 

[miamicuse]

The curve is listed in increments on the product page for each size pump:

View attachment 160402

Got it good catch. I was looking for a graph and missed the tabulated data.

By the way I found out that QuietDrive is basically Sequence but a private label made for a specific retailer.

 

[miamicuse]

I am getting closer to a new pump but have a few more questions.

(1) Head calculations - using the desirable flow rate of 3200GPH, or 50GPM, I redid the head calculations.
My own calculations = 26' head
Using FreeCalc.com calculator = 25' head
Using PowerZone.com calculator = 44' using Hazen Williams equation 31' Darcy Weisbach equation and 34' Fanning Chirchhill equation

I am thinking 25' @ 3200GPH of head is probably going to work so this is what I will look for.

(2) I found three that may work, EasyPro, LandShark and PerformancePro.

It seems the EasyPro GV75S or GV100S should work, Or the LandShark LS4600 or LS5500 should work. These are lower priced pumps and I don't know if they are any good durability wise.

The PerformancePro Artesian2 High Head pump will work too, but at double the price of the other two.

(3) One question I have, is when I called a pond pump retailer and asked about the PerformancePro, the phone rep told me that based on my configuration, he thinks the flow rate will be too high and resulting in more friction losses. He suggest that I install a 1-1/2" ball valve on the return to throttle the flow down. I don't understand this, if all the friction loss calculations were done based on a 3200GPH flow rate, then once we have everything calculated and picked the pump based on the head and flow rate hitting the middle section of these curves, and then if I slow the flow with a ball valve, doesn't that change the flow rate, and if flow rate is changed, all the previous calculations based on that flow rate are changed as well? I am missing something here.

 

[Pablo]

I think you will want to have a valve to control the flow. Gives you some flexibility. Dont worry too much about the friction loss etc. My setup is different because I have the pump feeding a bog but I did a wye fitting so two pipes are going to the bog. I did this because several people mentioned it here that it is a good way to control the flow to their bogs. So one pipe feeds the bottom of the bog and the other just goes to the top of the bog so I can add more flow to the stream and waterfall. I still have to figure the correct flow because I have too much water in the bog. But with the valves I can control it. You never know if you are off on your calculations and the pump is too strong so at least you have the valve to control things. I went with true union valves which are more expensive but much easier to turn than the large ball valves, 1.5 inch ball valve might not be too bad but I know the 2 inch was ridiculously hard to turn.

 

[miamicuse]

I think you will want to have a valve to control the flow. Gives you some flexibility. Dont worry too much about the friction loss etc. My setup is different because I have the pump feeding a bog but I did a wye fitting so two pipes are going to the bog. I did this because several people mentioned it here that it is a good way to control the flow to their bogs. So one pipe feeds the bottom of the bog and the other just goes to the top of the bog so I can add more flow to the stream and waterfall. I still have to figure the correct flow because I have too much water in the bog. But with the valves I can control it. You never know if you are off on your calculations and the pump is too strong so at least you have the valve to control things. I went with true union valves which are more expensive but much easier to turn than the large ball valves, 1.5 inch ball valve might not be too bad but I know the 2 inch was ridiculously hard to turn.

I plan on having a full port ball valve on the return but I wonder about using it to constantly throttle the flow. I also curious about variable speed pumps, is it worth considering since there is such a big range in the head calculations.

 

[combatwombat]

Variable speed pumps are great if you want variable speed flow. If you don't, then find a pump that's close enough to what you want and put a valve in line to dial it in.

I can appreciate your attention to detail, but we're building backyard ponds here, not Mars rovers. I get the sense that you want the perfectly engineered and installed system, but that you're not an engineer nor a master plumber. You might be causing yourself more problems than you're solving by trying to do things this way. What you create is going to be imperfect, but it'll still be a great pond.

I hope you don't take this as an insult. It's what everyone had to tell me over and over during my own build.

 

[Pablo]

Just noticed that Webbs has your Quiet Drive pumps on sale. You just have to be careful with their pricing because sometimes they begin higher, so double check with Underwater Warehouse, I know Quiet Drive is specific to Webbs.

 

[Pablo]

Variable speed pumps are great if you want variable speed flow. If you don't, then find a pump that's close enough to what you want and put a valve in line to dial it in.

I can appreciate your attention to detail, but we're building backyard ponds here, not Mars rovers. I get the sense that you want the perfectly engineered and installed system, but that you're not an engineer nor a master plumber. You might be causing yourself more problems than you're solving by trying to do things this way. What you create is going to be imperfect, but it'll still be a great pond.

I hope you don't take this as an insult. It's what everyone had to tell me over and over during my own build.

Lol, who would ever say that? It was great going through your thread and videos because you really analyzed everything so it was great learning. Even if not everything applies to a person's build, still learning.

 

[miamicuse]

Variable speed pumps are great if you want variable speed flow. If you don't, then find a pump that's close enough to what you want and put a valve in line to dial it in.

I can appreciate your attention to detail, but we're building backyard ponds here, not Mars rovers. I get the sense that you want the perfectly engineered and installed system, but that you're not an engineer nor a master plumber. You might be causing yourself more problems than you're solving by trying to do things this way. What you create is going to be imperfect, but it'll still be a great pond.

I hope you don't take this as an insult. It's what everyone had to tell me over and over during my own build.

No not offended at all, I appreciate all the advice and assist I have gotten here.

I am an engineer on my day job, but I design with highways, bridges and construction automation, not water supply and pumps. Obviously that is part of why I am over-analyzing and being OCD here.

Another reason I am more skeptical and careful is I already spent some $ on the Sequence pump and priming pot, which are not returnable. I did minimal research before I ordered them, and after a week of trying to get it to work and failed,, and I started to hear my wife ... "aren't you an engineer? You are supposed to know this stuff, and you didn't even order the right pump?" so I don't want to order another pump that I have to put aside.

But what is really puzzling me is all these friction loss calculations. How can one calculation says 20' of head ft and another 45' of head ft? Add to it the static head then you have 26' vs 51'. That's more than double. Then somewhere I read that add on another 10' if you may consider a filter...this is the reason I am struggling is this wide range of head needed.

I just learned something new a few days ago. I have noticed some pumps are self priming, and some are not. Those that are not self priming, they said you it's installed above grade, you need to add a priming pot. So I assumed, incorrectly, that adding a priming pot turns a pump that's not self priming into self priming. Now I know that's not the case LOL.