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Kengar
02/17/2015, 04:11 PM
Wondering whether the round, analog pressure gauges that screw into the side of the membrane housing go bad over time. Mine has been showing 70+ psi lately, and that is without a booster pump. Seems kind of high. (Membranes were replaced within last six months or so, so don't think it's a membrane blow-through issue.)

Thanks

SpectraPure
02/17/2015, 04:15 PM
There are at least several "failure modes" and an array of potential causes of "failure".

Before I guess from afar, er... troubleshoot... Does your gage read zero accurately when pressure is off of the system entirely?

bruce

Kengar
02/17/2015, 04:54 PM
Yes.

I would try swapping membranes from one housing to the other -- I have 180 gpd system with two membranes -- to see if it's membrane to "blame" but I think I would not be able to put membranes back into housing once pulled out.

SpectraPure
02/17/2015, 05:12 PM
You can put the membrane back in when you pull it out, but if you are producing good and bad water then typically the gauge is calcified. putting a very small amount of CLR in the orifice could break up the calcium.

Jeremy

SpectraPure
02/17/2015, 05:16 PM
ok then. If the zero is good, then the escarpment is unlikely to have been "jumped" which would cause the pressure reading to be faulty.

Do you know what your original pressure upon start up was? I assume this number to be lower than current readings as I assume this lead to your inquiry as to the "high" reading on your potential gage issues.

What is odd, is you are reporting higher pressures, and the most common failure mode is low readings, not high. High are typically associated with the jumping of the escarpment I mentioned earlier. Since your zero is spot on, it is unlikely the escarpment is jumped which could give you an artificial high reading.

Low readings are typically associated with a veritable plethora of causes, including calcium hard water build-up, foreign material, teflon tape over the inlet fitting, filter plugging, membrane bypassing, flush valves left in the on position, membranes blow thru, etc etc etc.

Where do you want to go from here?

A replacement gage is very inexpensive and may be a swift course of action to remedy your potential pressure question.

bruce

Kengar
02/18/2015, 10:26 AM
Hi Bruce,

Not sure what the escarpment is, but it sounds like it's the separator that keeps the product-water and effluent-water channels between the membranes separate.

Here is what caused me to raise the question. My Aquatec pressure booster pump sprung a leak (it was four or five years old or so), and I was going to replace it. However, according to the pressure gauge on the membrane housing, pressure was already at 70 psi. (At previous home, which is where I was living when I bought the booster pump, supply pressure was much lower, e.g., only 40 psi, which is why I bought the pump in the first place.)

I believe I had been told previously that 70 psi was about the max pressure you could get out of it anyway, so if I really am getting 70 even without the pump online, then no need to buy a new pump.

However, rate of production seems to be markedly slower without the pump online, which is why I am wondering if the gauge could go bad. I imagine the gauge uses a bourdon tube, and perhaps the tube is weakening somehow. (Although if that happened, perhaps I would see water fill the gauge......)

In any event, if gauges do go bad and they are relatively inexpensive to replace, it might make sense to put a new one on to double-check P before spending the money for a new pump.

SpectraPure
02/18/2015, 10:44 AM
Hi-
I should have explained, escarpment, like a watch. The bourdon tube connects to the dial ("needle") via an escarpment. If shocked, eg; a sudden high water pressure shock or from external shock (dropping/bumping/banging the gage physically) the escarpment gear can jump and present a incorrect reading. Since your zero is ok, I am doubting this occurred. Instead, since you are concerned that the indicated pressure may be reading falsely high, had the bourdon tube been distended (false high), typically the zero would be off.
If your gage was plugged partially, it would still reach ultimate pressure, not a false read. Since it goes to zero, I know it is not fully plugged.

I would suggest a new gage and then you are positive.

Your production loss comment is more troubling. Has your water temperature changed recently or upon the move?
Also, have you recently checked your waste ratio?

Your suspected production loss can be looked at more closely, we would be happy to help.
bruce

SpectraPure
02/18/2015, 10:59 AM
Kengar,

Please measure the good water for a minute, and then measure the bad water for a minute. Also let me know what the water temperature is. I can tell if you have 70 psi or not.

JEremy

Kengar
02/18/2015, 12:19 PM
Jeremy,

Not sure what you mean by measure the good and bad water. What are you referring to as the good water and what are you referring to as the bad water? Output/effluent? And if so, if you are saying to measure pressure, how would I measure that separately?

Thanks

Ken

Kengar
02/18/2015, 12:20 PM
Maybe a phone call would be easier.......

Will call in a bit.

SpectraPure
02/18/2015, 01:22 PM
Im sorry. Please measure the amount of water the system makes on the product side for 1 minute, and then on the waste side for 1 minute. I am looking for Milliliters per minute.

Kengar
02/21/2015, 10:22 AM
I haven't had a chance to measure flow rates. However, here's another piece of information.

I have the inline flush valve arrangement to selectively bypass the flow restrictor (to flush membranes) or force flow through restrictor (to make RO water). When I bypass the flow restrictor, gauge shows 40, which would seem to be spot-on for local supply pressure values. When I run through the flow restrictor, on the other hand, it goes to 70. Could 70 be correct, or does that suggest something is wrong in the flow-restrictor flow path, e.g., clogged restrictor (which would explain high pressure and low output)?

Kengar
02/22/2015, 11:51 AM
Here are further performance specs, measured with HM Digital COM-100 TDS meter (with temp measurement)

Final output values:
Product water: 500 ml in 98 seconds = 5.1 ml/sec, coming off the membrane at 50 F (114 gpd from dual membrane system)

Waste water: 500 ml in 34 seconds = 14.71 ml/sec, coming out at 52 or 53 F

Water temp going to the membrane = 45.8 or 46 F

Supply: about 220 ppm TDS at 52 F

Flow restrictor (yellow dot): 139 mm long (including portion that extends through the flanged fitting at the end)

rejection values:
To membranes (off of the carbon block, with some Cl showing (ordering new C today)): 217 or 218 ppm TDS

From membranes/to MaxCap: 3.2 ppm TDS at 50 F (99% rejection ("Select" membranes)

Off of MaxCap/to DI: 0.4 ppm TDS at 47.1 F

Off of DI (final product): 0.2 ppm TDS


Sooooo, performance values are looking generally pretty good, with fairly cold water supply. As noted above, supply is running at 40 psi, but it is kicked up to 70 in the membrane housing. Which brings me to the ultimate question, would a booster pump do me much good? Yes, it would kick up the pressure of what is being delivered to the membranes, but how much more output would that really produce? Increasing flow would have more drag (yes? no? not fast enough to matter?), which would offset the benefit? Thoughts?

Thanks for you help.

Ken

SpectraPure
02/24/2015, 02:31 PM
Yeah but those DI values are high. There is no decimal place. 4 tds coming out the maxcap should have been changed at 1 ppm. Also 2 out of the silicabuster should have not made it past 1 tds.

The flow rates on your system match up with 70 psi. This is normal for the flush to go down that much on pressure.

Jeremy

Kengar
02/24/2015, 04:07 PM
That, then, raises an interesting question re the MaxCap. I ordered a replacement SP MaxCap in the last month (Jan 16) from Sky Innovations, via Amazon. After installing it and running water through it (i.e., after I could return it), I noticed that the old cartridge I had taken out did not have any sort of tape around the upper perimeter, whereas the one I had just put in did have a wrap or two of what looked like white vinyl tape (e.g., electrical tape). That looked odd, like they might have repacked an old cartridge and sold it that way even though the listing on Amazon said new and it came in the SP foil pouch, so I asked the seller about it. They wrote back and said that DI cartridges are now coming that way; is this correct?

Actually, though, after having just written this I am now looking at the TDS meter again and it does, in fact, have decimal. For example, sitting on desk right now, it is displaying 0.0 I suspect you are thinking that I was taking the readings with the two gauges that came on the system, but I'm not. I'm using this meter: http://www.tdsmeter.com/products/com100.html. I tap off of the flow lines between the various canisters to take samples (T-valves installed into the various flow segments), and measure a large glass-full of water with the Com-100 meter.

And back to the question that led to this thread (sort of), would putting a booster pump on the system do much of any good in increasing output? Yes, it would increase supply from 40 to something more, but how much will that really affect throughput through the membranes (the most flow-limiting part of the device I would assume)?

SpectraPure
02/24/2015, 04:47 PM
For DI that doesn't read 0 off the bat we need to check to make sure that our meter is calibrated. If you know that your meter is reading right, then I would contact amazon and the seller. If there is ever a concern you can buy our di cartridges directly from us.

Jeremy

SpectraPure
02/25/2015, 11:02 AM
The manual has important information that you may find useful:

http://spectrapure.com/manuals/MAXCAP_RODI_MANUAL_REV_1_PF.pdf

specifically:
Maxcap replacement-
When the reading on the right-hand TDS meter (set to “IN”) displays 50%
of the reading on the left-hand TDS meter (set to “OUT”), it is time to
replace the MAXCAP® DI cartridge.
2. Make sure the DI cartridge is installed in the correct direction as marked
on the cartridge shell and be sure that the top seal is securely attached to
the top of the cartridge.
3. Tighten the cartridge housing by rotating it clockwise and hand tighten.
4. Turn on system and check for leaks.

the silica buster
Procedure:
1. When the reading on the right-hand TDS meter (set to “OUT”) displays
“001”, it is time to replace the SilicaBuster ™ DI cartridge.
2. Make sure the DI cartridge is installed in the correct direction as marked
on the cartridge shell and be sure that the top seal is securely attached to
the top of the cartridge.
3. Tighten the cartridge housing by rotating it clockwise and hand tighten.
4. Turn on system and check for leaks.

Additionally-
hand held meters like the com-100 require careful handling, correct calibration, and sanitary test vessels for best results. Please refer to your COM-100 manual for procedures to insure your reading is accurate, precise, and repeatable.
bruce