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# Thread: Fleck 9100 and well gpm questions

1. ## Fleck 9100 and well gpm questions

Hello.
I have a question about a well gpm and if I am understanding flow rates correctly for a Fleck 9100 water softener. I have a private well with a pressure tank and water softener that is plumbed with 1.25" copper. The pressure tank is set for 40/60 psi. Based on a site on the internet it stated "the formula for determining well flow rate: (Gallons drawn) divided by the (number of seconds timed for the pump cycle), then multiplied by 60 equals the gallons per minute (GPM) that your pump produces." Based on this I have 20.4 gpm (19 gallons /56 seconds)*60
I am looking to purchase a twin tank softener and found the Fleck 9100. Looking at the spec sheet for a Fleck 9100 http://www.pentairwatertreatment.com...et%2040821.pdf
it states for a flow rate (50 psi inlet) on a 1" meter, the continuous flow rate (15 psi drop) is 21gpm. Does that mean that the treated water coming out of the softener is 35psi? Also what does it mean by peak flow rate (25 psi drop) 1" meter 28gpm? My other question is if I got the 4 cu ft of resin in each tank would I get any hard water leakage if I were using the full 20.4gpm continuously? What is confusing me is a site I visited is selling a Fleck 9100 with 4 cu ft resin in each tank but rated the flow rate 16 gpm at a 15 psi drop. Why would it not be the 21 gpm as per the spec sheet?
I appreciate the reply.
Thanks,
Boudreaux

2. Is there a reason that you are looking at going so large?

That many bathrooms?

Turbo can only do so much, 17gpm is the peak.

3. Hello Akpsdvan
I plan to tap a couple of zones for irrigation for iron stains. There are six bathrooms. What is a turbo? So 17gpm peak means with the Fleck 9100 I will get leakage thru?
Thanks.
Boudreaux

4. Specifications about pressure drop as a function of flow rate for the Fleck 9100 control head relate to the head ONLY. So you are correct that at a flow rate of 21 gpm with a supply pressure of 50 psi the pressure comming out of the control head will be 35 psi. If the flow rate increases to 28 gpm with 50 psi supply pressure the pressure coming out of the control head will be 25 psi. Other components of the system (drop tube, distributor, and resin) cause additional pressure loss at high flow rates. Frankly, if you are looking for a system with flow rates in the 20+ gpm rate I would not recommend a Fleck 9100. You would do much better with the Fleck 7000 (not a twin tank model) with the high flow piston because it has much less pressure drop at higher flow rates or a commercial control head.

The second issue you raise is hardness leakage as a function of flow rate. You will find some differing views among the posters on this board. My view is that you will get satisfactory performace (acceptable hardness leakage) for a typical residential setting using a flow rate of 8 gallons per cubic foot of resin. So if your max flow rate is 24 gpm I would recommend a 3 cubic foot resin tank (based on flow rate only). Depending on your compensated hardness and daily water usage a larger resin tank might be indicated so you should post those parameters if you are looking for advice about sizing.

5. Originally Posted by boudreaux
Hello.
I have a question about a well gpm and if I am understanding flow rates correctly for a Fleck 9100 water softener. I have a private well with a pressure tank and water softener that is plumbed with 1.25" copper.

The pressure tank is set for 40/60 psi. Based on a site on the internet it stated "the formula for determining well flow rate: (Gallons drawn) divided by the (number of seconds timed for the pump cycle), then multiplied by 60 equals the gallons per minute (GPM) that your pump produces." Based on this I have 20.4 gpm

I am looking to purchase a twin tank softener and found the Fleck 9100. Looking at the spec sheet for a Fleck 9100 http://www.pentairwatertreatment.com...et%2040821.pdf

it states for a flow rate (50 psi inlet) on a 1" meter, the continuous flow rate (15 psi drop) is 21gpm.
The spec sheet is for the control valve (including a meter), not the entire softener. The spec sheet tells the dealer (that knows what they are doing) what size tanks the control valve can 'service'; it says Softener 6-16".

Originally Posted by boudreaux
Does that mean that the treated water coming out of the softener is 35psi? Also what does it mean by peak flow rate (25 psi drop) 1" meter 28gpm? My other question is if I got the 4 cu ft of resin in each tank would I get any hard water leakage if I were using the full 20.4gpm continuously? What is confusing me is a site I visited is selling a Fleck 9100 with 4 cu ft resin in each tank but rated the flow rate 16 gpm at a 15 psi drop. Why would it not be the 21 gpm as per the spec sheet?
You have to look at the whole softener, not just the valve spec sheet. Many dealers don't know how to size softeners or filters correctly. And then there are guys that don't sell either but have opinions because they have read spec sheets and what some dealers and incorrect web sites say.

You need to know what peak demand you have in gpm and then find the volume of resin in cuft that provides a constant service flow rate (SFR) of the softener that exceeds that peak demand gpm (and not at Bob's 8 gpm/cuft because SFR is on a curve, not a straight line as he obviously thinks).

Then if the 9100 is not the right choice you go to the 9500 etc. bUT....

Softening irrigation water is a bad thing because eventually the softened water will kill vegetation, including trees if not for the added sodium or potassium then the chlorides. You will also be using salt where an iron filter doesn't. And you say you have rust staining. Now two other guys here haven't mentioned any of the negatives of you using a softener... shame on them.

Also, you have to add all household water use gpm to the irrigation gpm to come up with your peak demand.

How much hardness, iron, any manganese is in your water and what is the pH? All that has to do with correctly sizing a softener also.

And why a twin tank type softener? Remember that they regenerate when you are using water. That may pull the well down more than 'normal' and that usually changes water quality and robs pressure until the regeneration is done. Pulling the well down farther than normal is usually not a good thing.

IMO you seriously need to rethink the choice of using a softener for irrigation water.

Leakage is a function of resin, not the control valve.

6. Originally Posted by Gary Slusser

You need to know what peak demand you have in gpm and then find the volume of resin in cuft that provides a constant service flow rate (SFR) of the softener that exceeds that peak demand gpm (and not at Bob's 8 gpm/cuft because SFR is on a curve, not a straight line as he obviously thinks).
As I indicated in my post there are varying views about appropriate sizing of the resin bed to achieve acceptable leakage rates.

I frankly don't know where Slusser gets his data ("because SFR is on a curve") --I have asked him to post the source or a reference a number of times but he just keeps asserting the information without documentation or explanation.

The basis for my recommendation is the data published by resin manufacturers which rates leakage as a function of flow per cubic foot of resin. If, for example, you look at the specification sheet for Purolite standard resin the basic ratings are for ~ 5 gpm per cubic foot of resin. However the leakage rates are very low-- considerably lower than necessary in residential service and there is no disagreement that flow rates well above 5 gpm/ft3 are appropriate for residential installations.

7. The fun never ends.............................................. .....

8. Originally Posted by Wally Hays
The fun never ends.............................................. .....
Sorry to take you away from your cartoons but I'm sure that if you apply yourself you could learn something about correctly sizing softeners.

9. Possible, but not here. In fact, with all the confusion, mis-information, ego's and arguing that goes on I'd be surprised if anyone can learn anything. But thanks for your concern. You pride yourself in your ability to size equipment but it always seems that no matter what site you post on your are always a majority of one. It's funny that of all the water filter professionals out there, you are the only guy that interprets the manufacturers data the way you do. So let's see now, everybody else in the world and then your way. You must be correct LOL

10. Originally Posted by Bob999
As I indicated in my post there are varying views about appropriate sizing of the resin bed to achieve acceptable leakage rates. I frankly don't know where Slusser gets his data ("because SFR is on a curve") --I have asked him to post the source or a reference a number of times but he just keeps asserting the information without documentation or explanation.
You fail to mention that you do not answer my questions and that I've told you that until you do don't expect to me to do any different.

Originally Posted by Bob999
The basis for my recommendation is the data published by resin manufacturers which rates leakage as a function of flow per cubic foot of resin. If, for example, you look at the specification sheet for Purolite standard resin the basic ratings are for ~ 5 gpm per cubic foot of resin. However the leakage rates are very low-- considerably lower than necessary in residential service and there is no disagreement that flow rates well above 5 gpm/ft3 are appropriate for residential installations.
And how do you come up with your 8 gpm/cuft Bob?

The constant SFR gpm of the SOFTENER is based on the total volume of resin in the softener. That makes it easier for a novice homeowner to understand instead of them having to have an engineering degree Bob. And you should note that most folks selling softeners talk in the misleading K of capacity, not cuft because they don't know better or don't want their prospective customer/customer to know anything other than the very little they tell them. Here we are talking softeners, not just resin as Purolite does but....

Check this out from Purolite (page 5 of the link below) BH/h is bed volume/hour, that is a tank full. Has anyone here heard of a household running water for hours on end? *******Residential systems often operate intermittently at flow rates of up to 80 BV/h (bed volume per hour) (10 gpm/ft3) of resin. Typical flows are much lower (average is closer to 20-30 BV/h) (2.5 gpm). As a result of higher flow peaks and the need to minimize brine usage lower regeneration levels are now being employed (120 g/l or less) (8 lbs/ft3), residential systems generally experience higher levels of
hardness in the effluent but still less than 20 mg/l (1 gpg (17ppm)).********

That says that your 8 gpm/cuft would not be correct Bob. And many residential softeners today are using much less than his salt dose of 8lbs/cuft of resin.

I keep telling ya but you insist you're right because I don't answer your question of where I get the constant SFR gpm PER SOFTENER info from... IMO, IF you were selling softeners, you would/should know where to get the info.

Bob, DO YOU SELL SOFTENERS?

Here's the Purolite link;
http://www.purolite.com/Customized/C...es/rid_339.pdf

You may also learn something from this (page 2 in the link below). Recall I told you 50% minimum expansion? Notice here we get into gpm per sq/ft of the resin surface? Can you find the error about brining in bold? How's 'bout the bed depth part that you have argued with me about in the past, the article agrees with me; I've put it in bold for you (2nd paragraph)?

********In service operation optimum performance is achieved at service flow rates between 8 and 40 BV/h (Bed Volumes per hour) or 1 to 5 US gpm/ft3 (US gallons per minute per cubic foot of resin) within linear flow rates (velocities) of 10 to 50 m3/m2/h (m/h) (4 to 20 gpm/ft2), whereas brine regeneration is carried out at flow rates of 2 to 4 BV/h (0.25 to 0.5 gpm/ft3). Within these limits internal distribution / collection systems can operate efficiently both at the higher service and lower regenerant flow rates. At very low service flow rates channelling can occur within the resin bed resulting in poor plant performance and short capacity between regenerations. This is particularly likely when long service cycles are also employed at these low flow rates.

While some small industrial and domestic softeners operate with very shallow bed depths, bed depths below 610 mm (2 ft) should be avoided and preferably bed depths greater than 1000 mm (3 ft 3 in) employed. Vessel height and pressure drop are normally the controlling factor on the maximum height of the bed. For Purolite C100 we recommend that pressure drop across the bed should be maintained at less than 150 kPa (22 psi), having made allowance for bed compaction and any solids loading across a classified bed. Bed depths greater than 2000 mm (6 ft 6 in) are rarely encountered. The ratio of height to diameter is important in any ion exchange unit design.

Although smaller freeboards are sometimes encountered, we recommend a minimum 75% freeboard (space) above the resin bed to allow at least 50% bed expansion during backwash. This is normally adequate for a co-flow regenerated vessel, and assures a good hydraulic classification of the resin bed.***********

Here's the link to the article;
http://www.purolite.com/Customized/C...es/rid_502.pdf

Someday I'm probably going to have to teach you to understand a control valve spec sheet Bob but with all that information above, now ya can commit it to memory and repeat it as if you size, sell and service softeners, or have sized, sold and serviced softeners in the past. And evertually you won't have anything to argue with me about.

11. Originally Posted by Gary Slusser

The constant SFR gpm of the SOFTENER is based on the total volume of resin in the softener. That makes it easier for a novice homeowner to understand instead of them having to have an engineering degree Bob.
That seems a lot like what I posted.

So what is the relationship between the gpm/ft3 and the volume of resin???

I said a softener can handle 8 gpm per cubic foot of resin--a linear relationship (this is for a residential application and with "acceptable" leakage.

You said it is a "curve" in an earlier post in this thread.

But when I look at the values you post they don't comport with your statement. The information in the attachment is taken from your posts about flow rates for varying sizes of resin beds and the gpm/ft3 has been computed. The gpm/ft3 ranges from 9 gpm/ft3 for a 1 cubic foot softner to 6.25 gpm/ft3 for a 4 cubic foot softner. But the relationship is not a "curve"--it is a jagged line!

Slusser curve.pdf

12. Originally Posted by Bob999
That seems a lot like what I posted.

So what is the relationship between the gpm/ft3 and the volume of resin???
The salt dose lbs/cuft is it.

Originally Posted by Bob999
I said a softener can handle 8 gpm per cubic foot of resin--a linear relationship (this is for a residential application and with "acceptable" leakage.
Your 8 gpm/cuft is inaccurate and you should have been able to see that in the Purolite articles I referenced.

The rest of your post with it's made up cuft figures (which are nowhere on my site) is useless. BTW, you have another error in the figures you used so now an error in addition to misleading people by misrepresenting those figures as my figures.

Originally Posted by Bob999

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