Putting in an overflow at the pad... how to?

[rtilghman]

I'm really worried we're not on the same page here Rick,





The returns of a pools plumbing are behind the pump, from pump back to pool. A passive overflow device and a non return will not work in the return lines as passive overflow and return flow are heading in the same direction.





Again, are we talking about the return or suction side of the pump but more importantly any skimmer I've ever seen has the plumbing connection communing out of the bottom of the skimmer.





I think it's the other way around, I was assuming you would have a connection on the back end of the overflow or U and its this piece that provides the flow and suction to drive the syphon. A lot of your existing plumbing would make up the front und of a syphon including all the way to the bottom drain. Expect the unexpected, it's not just a rain event that can cause the possibility of a syphon, someone jumping in the pool would be enough to flood that section and suddenly your draining your pool to waste!


It sounds easy to swap out an elbow for a tee but in practice it can be quite tricky and once you start cutting into your existing plumbing it will never be the same again. You can't just swap one for another, you'll be swapping one for several and every extra fitting adds head pressure to the pump. If you cut into your existing plumbing it is flooded and all the water in the pool will drain out to that point.


My preference would be to provide a dedicated connection to the pool for a passive overflow but I don't see the point of going to all the trouble if you don't get enough rain to overflow your pool in an hour or two. Maybe it would be better to make a permanent connection from the valve you currently use to drain your pool to your 6" drain pipe. If I were you I would get the original pool builder back to 'quote' on your idea and get his ideas or advise.


Non returns do fail and it can damage the pump and your system when it does costing lots to fix.


Cheers,
Steve.

Sorry, I can't stop laughing at the whole Returns vs Suction thing... sorry if it was confusing, I tend to type quickly, and when my brain is thinking of "returning water to the pad" it ends up coming out in my reply. I hope we've all got a good idea that we're talking about the SUCTION side of the pump. Anyway, while I don't have a lot of experience dealing with siphons, I do have a good amount of experience with broader plumbing, more than enough to rebuild small portions of my pool's plumbing... which is pretty basic, and which I already did to build in a pad based auto-fill.

One the confusion, yeah, this is a gravity based "open to waste" system on the back side of the suction side plumbing in front of the pump. I'm not concerned about jumping in the pool effecting this at all. The level changes from jumping will be relative, and will have little/no impact down pipe within the reservoir (which I think is a reasonable idea).

Anyway, I think I've got everything I need here in terms of ideas, just need to think through the best way to incorporate it given that my "best" access (free pipe) is in front of the suction side valves (meaning I'll have to either drain the pool or cap the skimmer/drains directly).

Thanks for the insights.

Best,
Rick

 

[rtilghman]

2 thoughts, without getting into suction side vs return side, instead of a check valve how about a normally open power actuated jandy, solenoid or ball valve on the drain line. The valve can be connected to your control panel on the same relay as the pump. When the pump is running the valve closes the wast line so it does not become a fountain. When the pump turns off the valve de energizes and opens up back to passive drain mode.

Second though going in a totally different direction if you have an auto fill how about converting it to a passive drain for the winter. If the auto fill is above grade like your skimmer take the float valve out of it and insert a snorkel (what I am calling it for some unknown reason) up to the level you want to maintain. At the house you insert a T in the line with a ball valve on the waist line. In the rainy season you turn the water off inset the snorkel and open the ball valve no laser level needed in fact the lower the line below the pool the better, as soon as the water level hits the top snorkel the draining stops. Only thing I don't know is will the line be large enough to drain fast enough for what you need and of course you have to have an auto fill to begin with. Bad diagram attached View attachment 44117

it's a good idea, but I'm looking to keep this as simple as possible (unpowered, pipe only, no fail). The goal here is just to make a really easy, no brainer, passive overflow system that'll will reduce by one the things I have to think about when it comes to my pool. One less thing to manage is more time I can spend relaxing, hanging with my kids, or working, all of which are more desirable (to me) than thinking about draining my pool, especially if I'm away for the weekend and a big rain hits.

And on that note, whether or not we regularly get enough rain for my pool to overflow in 2 hours is irrelevant here guys... the goal of any overflow system is to passively manage the water level, full stop. Having to go out and drain the pool manually when you could just install some piping to do it for you is ridiculous. The pool level rises to the coping over 5 hours in a heavy rain, I look at the rain and laugh, the pool relevels itself perfectly within 30 mins when the pump cuts out. I.AM.DONE.

Thanks for the help.

Best,
Rick

 

[AUSpool]

...I look at the rain and laugh, the pool relevels itself perfectly within 30 mins when the pump cuts out...

Have you done it already? I was a bit worried my idea was going to lead to the destruction of your plumbing without any gain. If you haven't done it yet I've had a couple of thoughts that may be of help.


As I see it the key to the whole thing working properly is the non return valve, what type and to a lesser extent, where to put it. I think the spring type ones will close to tight and not open to work as a passive drain. The springless type is the one you want but it needs to be installed close enough to the pump so the pump can suck it closed if you get what I mean. A Jandy installed horizontally with the spring removed, easy to service and fix if something gets caught in it.


A syphon relies on the falling water on the back side of the U to suck water up and over the U from the front side. I had always assumed you would connect the back side of the weir, overflow or U to your 6" drain which would form the back side of a syphon. But if you don't directly connect the weir to the waist pipe you will avoid any chance of creating a syphon. You can still have a waist pipe, just let the water drop out of the weir and into a surface drain or funnel thats connected to a waste pipe. I need to do this to my overflow.

Cheers,
Steve.

 

[rtilghman]

Have you done it already? I was a bit worried my idea was going to lead to the destruction of your plumbing without any gain. If you haven't done it yet I've had a couple of thoughts that may be of help.


As I see it the key to the whole thing working properly is the non return valve, what type and to a lesser extent, where to put it. I think the spring type ones will close to tight and not open to work as a passive drain. The springless type is the one you want but it needs to be installed close enough to the pump so the pump can suck it closed if you get what I mean. A Jandy installed horizontally with the spring removed, easy to service and fix if something gets caught in it.


A syphon relies on the falling water on the back side of the U to suck water up and over the U from the front side. I had always assumed you would connect the back side of the weir, overflow or U to your 6" drain which would form the back side of a syphon. But if you don't directly connect the weir to the waist pipe you will avoid any chance of creating a syphon. You can still have a waist pipe, just let the water drop out of the weir and into a surface drain or funnel thats connected to a waste pipe. I need to do this to my overflow.

Cheers,
Steve.

I haven't done it yet... this isn't a project I'm going to rush, I'll probably try first to coordinate it with any pool draining I may need to do in the future (there are some plaster issues the builder has to solve).

If that doesn't happen I may end up doing it with the pool full, but I'd really like to avoid that since I don't want to have to coordinate removing grills from and plugging all the drains if I don't have to since, as I mentioned, I'm going to have to cut into and replace my main intake valves. Basically my intake side is tight where it surfaces at the pad, with elbows and Ts butting up against one another and the valves touching those. I'll basically have to cut the intake pipes just below the valves and the pipe behind the pump, then replace the entire assembly (three pipes, each with valves, and the auto-switch valve for the pool/spa cutover). It's frustrating, because all I really need is to change the elbow to a T above the left intake pipe (I think it's the skimmer), but there's no room to do it any other way.

As for the overflow, I'll connect that exhaust to the waste system at one of the vertical drain pipes that sit by the pad (they run 3' to the 6" drain pipe that runs to the street). As I mentioned, I'm not really concerned with a siphon effect if I have the passive repository behind the check valve, but just in case I'll probably also mount a control valve in front of the check valve... that way in an emergency I can cut the entire assembly off from the system and avoid having any standing water (I'll also be mounting a drain c0ck on the bottom of the overflow assembly so I can empty it when needed).

Got a plan, just need the parts and scenario to make it happen. Thanks again for the insights and advice.

Best,
Rick