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View Full Version : Have Maxcap Dual Stage; How to Upgrade for Auto-Refill of Reservoir?


Kengar
09/21/2015, 06:22 PM
Hi Bruce,

I have 180 gpd (dual membrane) MaxCap RO/DI system. I also have an 8800 pressure-booster pump upstream of the unit. (System pressure reads 60 or 70 even without the pump and goes to 80 with it, so don't really NEED it, just had it from old house with lower supply pressure and like the faster production rate.) Currently, I just make water as I need it, but I would like to automate resupply.

My understanding has been that you don't want to do an automatic, on-demand setup (e.g., with single float valve in the sump) to resupply fresh water directly into the sump and leave water on -- perhaps with a solenoid to control flow from supply to the RO/DI unit -- because initial water out will have impurities. (See, e.g., first sticky on this forum.)

I had always assumed the impurities were from water sitting in the final DI cartridge, but reading other stickies indicates it's actually coming off the membrane due to osmotic pressure across the membrane even while the unit is sitting Are impurities coming off of the membrane only, or is the final DI also source of impurities? In other words, when I run my system to "clear" it before collecting product water, am I doing that just to flush membranes, DI, or both?

In looking at some of your products and their corresponding manuals on your site, I can't tell (because I haven't digested the information thoroughly enough I guess) whether the flush cycle that is accomplished with the UHE setups is a flush of the DI, of the membranes, or both. Also, some of the models that are not UHE (e.g., MaxCap models) are identified as -AF, for autoflush. Are those models flushing the same element as is flushed in the UHE models?

At page 7 of the UHE manual, you show fresh water storage tank with two float valves that control solenoid(s), and I'm GUESSING that this arrangement facilitates automatic refill OF YOUR FRESH WATER STORAGE TANK (i.e., makeup reservoir), and that some other mechanism (e.g., float-switch-controlled pump or float-valve in sump) needs to be provided to transfer water from the reservoir into the sump to make up for evaporation.

However, I don't see a similar diagram in the Maxcap-AF Manual, so I'm not sure whether similar arrangement to automatically refill makeup water reservoir can be accomplished with it.

So, I guess my questions at this point are what feature/design element, precisely, makes a system a UHE system? What is being auto-flushed (just membrane or membrane and DI)? Is the autoflush responsible for increasing efficiency, or does UHE system somehow recycle some of the waste water to get a little more fresh product out of it instead of throwing all of the waste down the drain?

With my current system, could I retrofit it to automatically fill reservoir and do so without putting startup impurities into the reservoir? What would I need to do this? Since I have the booster pump already, which I see as part of the UHE system, could I retrofit it to be a UHE system, too?

Would it be easier just to discuss by phone?

And remember, will work for products! :)

Kengar
09/22/2015, 08:07 AM
Having read further, it appears primary difference between UHE configuration and "regular" auto-flush implemented on a MaxCap configuration is that in the UHE configuration, the flush cycle pulls fresh water from the reservoir, via the pressure-booster pump (peristaltic, so it can draw in this manner), instead of just opening up high-speed bypass flow around the restrictor to flush membrane. And since you're controlling more solenoids to effect this flow pattern, you need more "information" by having two float switches in the resrervoir instead of just relying on simple back pressure (per non-UHE version) when water rises in reservoir to shut off flow.

In all cases, then, it appears the flushing is of the membrane and NOT DI, so I guess the concern is not leaching of adsorbed ions back into water just sitting in the chamber while system is not in use.

Follow-on question. If it's the flow-restrictor that controls and makes the UHE system UHE by allowing 1:1 flow, why can't you run a "regular" max-cap system, e.g., with auto flush, at that rate? Does using pure water to flush the membrane keeep things "cleaner" so that you can reduce the amount of water you need to throw out?

Given that I have 8800 booster pump already, i could fairly easily retrofit to a UHE system, correct?

Thanks.

Ken

SpectraPure
09/22/2015, 09:39 AM
http://spectrapure.com/DOSING-TOP-OFF/FLOAT-SWITCH-CONTROL-RESERVOIR-FILL-SYSTEMS/Dual-Float-Solenoid-Valve-Controller-Assy-w-1-8in-Sol-Valve

Here is a kit that will allow you to autofill your reservoir.

Please let me know if you have any questions at all!

Jeremy

Kengar
09/22/2015, 09:47 AM
That kit does not appear to have enough components to pull from fresh water reservoir to flush the membrane. Is there another kit that does that, i.e., retrofit up to UHE?

As noted, I have the booster pump already. Would need a 1:1 flow restrictor and the appropriate set of solenoids to control flow.

SpectraPure
09/22/2015, 09:51 AM
Kengar,

That system only flushes the membrane you are correct. If you want to convert your Maxcap to a uhe it takes a lot more than a flow restrictor and a control module. You would have to send in your system for upgrade, and it will have to be completely redone. The cost of this is around 500 dollars. However I do have UHE 100 on sale for 749.99 phone or email orders only. You could probably sell your Maxcap AF with booster pump for about 300-400 on reef central depending on the condition and filter condition.

Jeremy

Kengar
09/22/2015, 10:03 AM
Jeremy,

Per preceding post, I would also need the appropriate set of solenoids, i.e., what's shown on page 6 of the manual as solenoid 1 and 2, with the pressure regulator. (I'm assuming that that's a single unit with both solenoids.) I assume solenoid 1 controls input source to the membrane, i.e., off of the carbon pre-filter or being drawn back out of the reservoir, and solenoid 2 controls whether membranes are being flushed by selecting whether flow bypasses restrictor or not.

Assuming this is correct, wouldn't it be possible to purchase the solenoids (assembly?), control module, two-float float-switch kit, restrictor, and bulkhead kit for water input to and water out-take (for flushing) from the reservoir, instead of having to send unit in?

SpectraPure
09/22/2015, 10:32 AM
Kengar,

This is something that you would have to send in to have built by us. I am sorry. The charge will be about 500 dollars, or there is the other option.

Jeremy

Kengar
09/22/2015, 10:36 AM
Is there something I'm missing in my understanding of the required components and design?

SpectraPure
09/22/2015, 11:00 AM
Kengar,

We do the rebuilds here. We never have sold these manifold blocks or control modules individually. We test the system for functionality after we build it. Management will not allow the end user to make this conversion. This is not as simple as it seems. So you can buy the UHE on sale, and sell yours, or send yours in for the upgrade.

I spoke with the President of the company, and he reaffirms this. Sorry my friend. I wish it were that simple. There are manifold block tied in with a pressure relief valve that are specially oriented.

Jeremy

Kengar
09/22/2015, 11:06 AM
what about retrofit kit to perform auto-fill operation (high and low float switched) with auto flush of the membrane WITHOUT pulling from fresh water reservoir, as per the MaxCap-AF setup? i.e., just switches solenoid valve to port flow around the restrictor for a period of time? is that available? (P.S. Thanks for your patience here as we flush out -- get it? flush out! :) -- options.)

Kengar
09/22/2015, 09:29 PM
???

SpectraPure
09/22/2015, 11:56 PM
Kengar,

We do not sell Automatic flush parts, or uhe parts. If you want to send the system in to be upgraded we do that.

Jeremy

Kengar
09/23/2015, 07:32 AM
Thanks for the further information. It had not been clear that upgrade to simple auto-flush also requires the unit to be sent in.

What would the cost be for that?

Re upgrading to UHE, what would the cost be if I send my booster pump in with the unit? It is 8800 and fairly new (less than six months, never run dry). Still $500, or less because I already own that component of the UHE system?

Thanks.

SpectraPure
09/23/2015, 09:30 AM
The price goes down to 450 with the booster pump on the uhe.

The price for the AF is not worth it. $175 then you have to buy the float assembly for 159.99. also the transformer is different for the booster pump on an af set up....

The UHE conversion is a much better deal, and you get so much more with it. This price includes the dual float.

Jeremy

Kengar
09/24/2015, 09:30 AM
PM sent.

Ken

SpectraPure
10/13/2015, 10:41 AM
Thank you. Hope this helped.

Kengar
10/13/2015, 04:22 PM
The new unit is very nice indeed. Quality workmanship, and I can see why it's something that is best left to you guys to provide.

Pleased indeed.

Ken

SpectraPure
10/13/2015, 04:44 PM
Thanks Ken,

I am glad you went with a new unit! If you have an questions please feel free to ask.

Jeremy