Intelliflow VF and venturi feeders

[malaxi]

Hi everyone,

I've inherited an older 27K gallon in-ground pool with a brine tank chlorine generator ("Pool Perfector").
I bought an Intelliflo VF pump to replace the older pentair pump that its using now, with the goal of drastically reducing the electrical costs of running the pool.

However, after I bought the pump (of course!), it dawned on me that the chlorine generator relies on a "venturi feeder" to pull the chlorine brine/gas from the brine tank to the water returning to the pool. In essence, it's a reducing fitting in the return line with a drip line from the tank.

As I understand it, the point of pumps like the Intelliflo VF is to move water at a lower pressure and lower velocity, thus using less electricity.

Anyone have any thoughts on whether the VF will work with the venturi feeder? And, since there is a pretty big reduction in flow there which I assume will increase water pressure behind it, will that negate the value of the pump?

Thanks!

 

[spishex]

It won't negate the value of the pump. Even running at the same GPM that your old pump was moving you'll still save money relatively. Does your venturi assembly look something like this:

...where the venturi itself is in a small, adjustable bypass? If so you may be able to make the necessary adjustment with the bypass valve to get the venturi's inlet pressure up where it needs to be. Performance varies by injector, and I'm not sure what kind of suction you need to pull the chlorine gas out (does the literature for the brine tank happen to say?), but I'd bet that if you're moving enough water to run two skimmers and a main drain that you'll have enough pressure for the venturi.

 

[malaxi]

Thanks for the response. Yep, it's that same sort of setup with the bypass. I've attached a picture. I'm glad to hear you think it'll work. I don't have the docs for the Pool Perfector, so don't know what pressure it requires. I can tell when it's working, though, because I get fine bubbles at the returns in the pool.

There is only one skimmer in the pool and, interestingly, as far as I can tell the pump is only pulling from the skimmer and not the main drain (no suction at the drain when the pump is running). After clearing some overgrown ivy around the cement platform that the pump is placed on, I found a capped stub of a pipe coming up out of the cement a few feet away. I suspect that there was a heater in place at one time, and the main drain was plumbed in to the system back then.

My plan for spring is to replace the pump and also see if I can plumb the main drain back in so the pump can draw from both the skimmer and the drain.

Thanks again!

 

[Richard320]

There is only one skimmer in the pool and, interestingly, as far as I can tell the pump is only pulling from the skimmer and not the main drain (no suction at the drain when the pump is running).

Are you sure?

I, too, am suddenly a pool owner, since it came with the house. I couldn't figure out where my drain went, either, but I discovered it by asking here. Inside my skimmer, there are two pipes. One goes to to main drain. Pull the basket in your skimmer and have a look.

 

[malaxi]

There is only one skimmer in the pool and, interestingly, as far as I can tell the pump is only pulling from the skimmer and not the main drain (no suction at the drain when the pump is running).

Are you sure?

I, too, am suddenly a pool owner, since it came with the house. I couldn't figure out where my drain went, either, but I discovered it by asking here. Inside my skimmer, there are two pipes. One goes to to main drain. Pull the basket in your skimmer and have a look.

I did check in the skimmer, and the other outlet/inlet is plugged. It's got a removable plug, but I haven't been brave enough to remove it to see what happens.

Well, I guess a little experimentation come spring is called for. I wonder how dangerous (for the plumbing) it would be to put an air fixture on the capped pipe by my pump and pressurize it? See if bubbles come out my main drain...

 

[spishex]

That's how I'd test the line.

You'll need about 40 GPM for a 12 hour turnover, so that's roughly enough to run 3 suction fittings if you had them. I think at that speed you'll be good to go.