Venturi Injector for LQ

Sabot

0
LifeTime Supporter
Aug 2, 2007
342
Austin, TX
Some users of the LQ are not getting enough "juice" out of their tank. Here is another option to research and test: Use of a venturi-type injector to get the "juice" out of your tank and into your pool. Mazzei Injectors was recommended to me by a number of folks in the industry. ( http://www.mazzei.net/products/typ_install.htm ) You will need a control valve between the injector & LQ. From what I have read and was told, if you don't the LQ will be sucked dry.
 
I was thinking of this same thing but didnt know it was used for liquid also. I have a mazzei injector on my spa that is used to inject the ozone from my ozinator. I figured it wouldnt work because it was injecting a gas not a liquid.

Maybe this will help those that need more chlorine added at a faster pace. You maybe onto something there sabot. EDIT: Maybe you have something here more you can tinker with now sabot.

Think maybe that installing this mazzei injector in a bypass with an electric gate valve that is shut half way for a determined amount of time, to make the pressure differential, until the proper amount of chlorine for you pool has been added. Then have the electric gate valve open fully after the predetermined amount has been injected, which in turn will shut off the flow of chlorine to the pool through the mazzei injector and wa-la, you have added the proper amount of chlorine for the day that you normally would have added by pouring the chlorine in manually. Plus this may stop some of the guys from getting air into their system which makes their pump lose its prime. I maybe need to run this one by the patent office!! LOL Im sure someone has a patent on it already though :wink: END EDIT

FWIW it seems to work great on my spa as I dont use alot of chemicals at all in it because of the ozinator.

Brian
 
Sabot said:
Some users of the LQ are not getting enough "juice" out of their tank. Here is another option to research and test: Use of a venturi-type injector to get the "juice" out of your tank and into your pool. Mazzei Injectors was recommended to me by a number of folks in the industry. ( http://www.mazzei.net/products/typ_install.htm ) You will need a control valve between the injector & LQ. From what I have read and was told, if you don't the LQ will be sucked dry.

Now you have my attention. This is exactly what I need. Followed the link and I am still a little confused. I need to do some more reading I suppose. Thanks for the idea!!
 
Hey, new to the forum and the LQ.

I had a nice write up about about how I went from a flow of "2" to "5" using the stock control valve, stock flow meter and one stock check valve on the inlet...but I accidentally closed the wrong tab and lost all my typing :(

The story is simple. Move to 3/8 inch line slid over 1 inch or so short pieces of 1/4 inch tube on the check valve, flow meter and control valve. Slid the 3/8 inch line on top of the outside of the floats after applying some pipe dope. Keep everything from moving with some tight small cable ties.

The pressure loss on 10 ft of 1/4 inch tube is around 5.8 PSI @ a 1 GPM flow rate. WIth 3/8 inch tubing that loss drops to 0.73 with the same flow rate. If you increase the flow to 2 GPM the 1/4 inch losses over 22 PSI, the 3/8 inch looses 2.7 PSI. You can see how you would hit a brick wall with the 1/4 inch line. No matter how hard you try you will not obtain anywhere near the same flow with the same inlet and outlet pressures.

I'm still using the 1/4 inch flow meter, one check valve and control valve. The distance and friction loss is not as great with a tiny distance of 1/4 passageway. 1 ft of 1/4 inch only drops about 0.58 PSI @ 1 GPM rate and only 2.22 PSI @ 2 GPM rate.

For reference I'm using this page to get my numbers. They are not going to be exact, but I think the truth still holds.

Pipe loss calc

I plan to order a 3/8 inch check valve and control valve from US Plastics to replace my 1/4 inch versions. I found the exact same control valve on their site that came with my LQ.

Here

I hope this info helps anyone trying to figure out their LQ. It also will make the "white stuff" have far far less impact on the overall system.

Thanks,

Rabbit
 
The Mazzei will work. I experimented with them several years back. I didn't wind up using one on my pool long term or introducing the product but I do have one in my sprinkler system to inject liquid fertilizer.

There is a version sold for commercial pools called "The Solution".

They will suck chemical in VERY fast. Slowing it down is the biggest challenge. I used a mini needle valve in the suction line.

They operate based on a pressure differential and the "suction power" thus the flow rate of your chemical is dependent on the differential. I found that in a lot of cases there were enough minor changes to the flow in the circulation system that getting consistent flow out of it was tough without using a booster pump in an independent bypass, much like a Polaris system.

Even stopping water flow to it doesn't guarantee you will shut it off in some cases, depending on the install it will continue to siphon.

I found the best way to insure no flow when off was to us a NC chlorine resistant solenoid valve (ball or diaphragm) in the suction line.

Clogging can also be an issue and in many cases (particularly depending on the quality of the bleach) it will need regular cleaning/descaling.

Bottom line, after developing it to the point of commercialization to get the consistency and safety required it wound up costing more than a metering pump. The only real advantage was that it could inject a lot more in very large applications, like waterparks, for less cost than the several metering pumps that would have otherwise been required.

All that said it's a solid concept, and I'm sure if you like to tinker you can come up with a homebrew system that will work well on your pool. Trying to standardize though is another issue.
 
Rabbit said:
Hey, new to the forum and the LQ.

I had a nice write up about about how I went from a flow of "2" to "5" using the stock control valve, stock flow meter and one stock check valve on the inlet...but I accidentally closed the wrong tab and lost all my typing :(

The story is simple. Move to 3/8 inch line slid over 1 inch or so short pieces of 1/4 inch tube on the check valve, flow meter and control valve. Slid the 3/8 inch line on top of the outside of the floats after applying some pipe dope. Keep everything from moving with some tight small cable ties.

The pressure loss on 10 ft of 1/4 inch tube is around 5.8 PSI @ a 1 GPM flow rate. WIth 3/8 inch tubing that loss drops to 0.73 with the same flow rate. If you increase the flow to 2 GPM the 1/4 inch losses over 22 PSI, the 3/8 inch looses 2.7 PSI. You can see how you would hit a brick wall with the 1/4 inch line. No matter how hard you try you will not obtain anywhere near the same flow with the same inlet and outlet pressures.

I'm still using the 1/4 inch flow meter, one check valve and control valve. The distance and friction loss is not as great with a tiny distance of 1/4 passageway. 1 ft of 1/4 inch only drops about 0.58 PSI @ 1 GPM rate and only 2.22 PSI @ 2 GPM rate.

For reference I'm using this page to get my numbers. They are not going to be exact, but I think the truth still holds.

Hey I think Rabbit has figured a way to increase flow!! Nice work Rabbit. Post some pics please.

Pipe loss calc

I plan to order a 3/8 inch check valve and control valve from US Plastics to replace my 1/4 inch versions. I found the exact same control valve on their site that came with my LQ.

Here

I hope this info helps anyone trying to figure out their LQ. It also will make the "white stuff" have far far less impact on the overall system.

Thanks,

Rabbit

I think Rabbit has created an easy fix for the low flow problem some of us are having with the LQ. Any pics Rabbit?
 
Here is some photos for what I did to adapt the 1/4 inch ID devices to 3/8 inch.

Step one, cut a short piece of 1/4 inch line (same stuff that came with the LQ)
step1.jpg


Step two, slide that small piece over the existing valve, control, etc.
step2.jpg


Step three, slide the 3/8 inch line on top of the 1/4 inch line. The 1/4 inch line is 3/8 OD.
step3.jpg


Step four would be to tie a small cable tie around the hose to keep pressure from blowing it off.

I actually had to use a pair of vise grips to take apart a hose I put together this way. I was amazed at how well it held. I also have pressure tested to over 25 PSI without a single leak. Not one drop.

I'll post more info on how to convert the tank to 3/8 inch and also the pipe fittings once I have some daylight.

I did some more mods today that I'll explain later that allowed me to get to what would be considered a "6" on the flow gauge.

More to come.
 
Ok, so I took a few more pics to help explain things.

I'll start with the flow

IMG_4028.jpg

Notice I replaced the fittings with 3/8 ID. They screwed in with the same exact type of pipe thread as the ones supplied with the EQ. They are just standard pipe thread.

Note: I am using brass for a couple weeks until I can get the same in plastic from US Plastics.
Do NOT use brass.

Inlet side of the tank. Notice the 3/8 lines pushed right over the ends with some pipe dope on the threads. The pipe dope keeps a spiral down the threads leak.
IMG_4025.jpg


Outlet side (the same thing as above)
IMG_4026.jpg


Picture of filter pressure gauge for reference, just because.
IMG_4027.jpg


Here is tapped in to the pump suction side right after my Jandy valve. (Again, don't use brass) You will need a pipe tap to do this right and lots of Teflon tape.
IMG_4036.jpg


Here is the outlet side that goes down kind of around behind the filter with one of the supplied check valve installed much like my last post (above). Kind of a sloppy job on my part..but it doesn't leak :)

IMG_4038.jpg


The original control valve with 3/8 inch line attached. Note that I used black and clear tubing only because I had some of the black stuff lying around. I felt there was no reason to redo my work once I purchased more clear 3/8 ID tubing. The black tubing is a bit thicker wall then the clear stuff as well. I would encourage it's use.
IMG_4041.jpg


Here is an overall pic of the unit itself. Yes I painted it white to keep some of the sun out. It's mostly shaded during the day, so it's not much direct sunlight. I left a stripe down the side so I can check the chlorine levels.

IMG_4040.jpg


I think that's about it for now. Let me know if you have any questions.

Thanks,

Rabbit
 
Rabbit said:
Hey, new to the forum and the LQ.

I had a nice write up about about how I went from a flow of "2" to "5" using the stock control valve, stock flow meter and one stock check valve on the inlet...

Good job, Rabbit. I wonder, did you have a max flow of 2 initially, and if yes, do you have an idea why? I have WS but I can reach flow rate of 5 easily if I wanted.Some people can't.
 
Water_man said:
Rabbit said:
Hey, new to the forum and the LQ.

I had a nice write up about about how I went from a flow of "2" to "5" using the stock control valve, stock flow meter and one stock check valve on the inlet...

Good job, Rabbit. I wonder, did you have a max flow of 2 initially, and if yes, do you have an idea why? I have WS but I can reach flow rate of 5 easily if I wanted.Some people can't.

I know why, the pressure on my return line was too low. Inside the filter is only around 8 PSI most of the time and by the time it gets to the outlets it's even less. It's not an issue with my pump being too weak, more an issue with my 48 sq/ft FNS plus filter being too free flowing.

I was able to get to a 3.5 or 4 if I filled the LQ tank manually before the 3/8 inch line. I could not keep above a 2 once the water level dropped (was filling too slow). So now with the larger line I'm having less pressure drop and more gallons per minute and a nice 5+ reading. Better suction and better fill rate.
 

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Rabbit said:
Water_man said:
Rabbit said:
Hey, new to the forum and the LQ.

I had a nice write up about about how I went from a flow of "2" to "5" using the stock control valve, stock flow meter and one stock check valve on the inlet...

Good job, Rabbit. I wonder, did you have a max flow of 2 initially, and if yes, do you have an idea why? I have WS but I can reach flow rate of 5 easily if I wanted.Some people can't.

I know why, the pressure on my return line was too low. Inside the filter is only around 8 PSI most of the time and by the time it gets to the outlets it's even less. It's not an issue with my pump being too weak, more an issue with my 48 sq/ft FNS plus filter being too free flowing.

I was able to get to a 3.5 or 4 if I filled the LQ tank manually before the 3/8 inch line. I could not keep above a 2 once the water level dropped (was filling too slow). So now with the larger line I'm having less pressure drop and more gallons per minute and a nice 5+ reading. Better suction and better fill rate.

Looks great. Thanks for the pics. You were able to find non-brass fittings? Could you provide a link?

Water_man,
I also am unable to get more than "3" on my flow meter. The reason in my situation has to do with an "over efficient" setup. My pump doesn't have to work very hard to return the water. With 2 main drains and 2 skimmers in close proximity to the pump, water is delivered to the pump already under pressure. Therefore the pump pulls from the LQ @ a lower flow rate. To illustrate this...as I turn off my skimmers or main drains the flow through the LQ proportionally increases.
 
revstriker said:
I noticed that you stated a couple of times to not use brass fittings. Can you elaborate on this?

Well mine are already turning black after about 3 days. The chlorine eats them away. I'll be ordered new fittings as well as a 3/8 inch ball valve to replace the 1/4 inch one. The company I mentioned above has the exact same one that shipped with the EQ as well as larger ones.

Like this one Here

I've been really busy lately so I'm having to do many short posts. Sorry about that.

Edit: I'll also order a 3/8 inch check valve for the inlet side. No such things as too much flow.
 
Just ordered my plastic items from US Plastics

Code:
62175	Male Adapter Nylon Fitting	6	$0.66	$3.96	
 	64197	Female Adapter Nylon Fitting	2	$1.10	$2.20	
 	22126	Buna-N-Seal/End Conn. 3/8" HB 2 Way Ball Valve, 3 1/4" x 1 3/4"	  1	$6.97	$6.97	
 	22231	1/4" FNPT Polypropylene Check Valve	1	$5.87	$5.87	
 	62158	Plug Square Head Nylon Fitting	2	$0.49	$0.98

Total was just over $30 with shipping. Two of the 62175's are for the check valve, two for the pipes and two for the flow meter.

The plugs are to put in the holes I had created when I first installed the unit and had no clue what I was getting in to :) They will replace the brass ones that are doing that job now.

The 64197's should screw in to the ends of the floats. If they do I'll be very happy. Not that my current setup leaks...but I kind of like the idea of having something more up to the task.

Edit: This was revised as I ordered the wrong NPT pipe sizes. You want 1/4 inch. NPT pipe sizes are very confusing. 1/4 inch is 0.540 inch. Go figure.
 
DLSDO said:
I also am unable to get more than "3" on my flow meter. The reason in my situation has to do with an "over efficient" setup. My pump doesn't have to work very hard to return the water. With 2 main drains and 2 skimmers in close proximity to the pump, water is delivered to the pump already under pressure. Therefore the pump pulls from the LQ @ a lower flow rate. To illustrate this...as I turn off my skimmers or main drains the flow through the LQ proportionally increases.

I'm not an expert on flow calc etc. but common sense tells me that the solution may be to make life harder for your pump. What about reducing the return line coming to the pump from say 1 1/2" to 3/4". I mean just the last couple of feet,
and then install the LQ's "outlet" saddle fitting (a Hayward improved version as I had posted before) on the 3/4" line on the pump's suction side. Just a thought.
But Rabbit's idea is easier to install and it's worth a try.
 
Water_man said:
I'm not an expert on flow calc etc. but common sense tells me that the solution may be to make life harder for your pump. What about reducing the return line coming to the pump from say 1 1/2" to 3/4". I mean just the last couple of feet,
and then install the LQ's "outlet" saddle fitting (a Hayward improved version as I had posted before) on the 3/4" line on the pump's suction side. Just a thought.
But Rabbit's idea is easier to install and it's worth a try.

Ya, I was able to get things working somewhat ok if I shut down the output valves on my returns. The pressure would go up and the LQ would work a bit better. It still didn't work as well as it does now. Also I would be pushing less gallons per day through the filter and increasing my electric bill :(

Ok..now let me place a new order with US Plastics with the right size pipes this time ..sigh
 
fixit5561 said:
Hey Rabbit,

What happened to your pictues in the thread?

I wanted to look at them again and they are gone.

Brian

Hmm, not sure. I may have had a server outage or something at the time you visited. Let me know if they are showing up now.
 
yep they are there now thanks

A question. Does the ball in your flow meter sit at the top of the water level in the flow meter or below it about the middle or a little better than the middle of the water level?


Brian
 

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