Purpose of Unusual Jets

[Bumpin96monte]

We bought a house with an in ground concrete pool a few years ago. Thanks to this forum, we've got water chemistry spot on.

I'm posting this as we've got two jets that I never understood. The outlet of the pool pump/ filter splits into 3 branches, each of which has a separate shutoff valve:
-the biggest pipe feeding the usual discharge outlets all around the pool walls
-two cooling sprayers mounted into the deck
-two regular size discharge outlets around mid back in one of the seating areas

It's the last one that confuses me. For some reason, the pipes feeding those two 'jets' in the seating area have a T in them with a vertical open pipe (3/4" ID?) coming out of the pool deck about 18" in from the edge of the pool. Those pipes are cut flush with the pool deck.

I thought they were intended to be focused jets to massage your back like in a hot tub, but they're 100% useless for that purpose:
1.) With the main outlets on full blast, even turning these on 100% only yields a small portion of the pressure from the regular outlet holes. The feed pipe coming off the pump to them is much smaller / flows less, and the outlet covers are full size outlet eyes (1" openings?).
2.) If you sit in front of them and get your back too close (under 2" or so), the backpressure causes the water to start streaming out of the vertical part of the T - making a mess of water all over the pool deck.
3) If you choke off the main discharge outlet valve a bit, you can force more flow/pressure to these 2 (although I'm careful how much I do that to avoid straining the pump too much). But before they even get to the full outlet pressure the regular discharge outlets see, the backpressure from the outlet eye cap causes a lot of water to stream out of the vertical pipes.


I'm certain those two open vertical pipes aren't intended to normally have water coming out of them as it just makes a puddle / stream heading towards the drain (i.e. its not intended to be some kind of splash pad fountain for kids or something).

I'm just curious if anyone has seen something like that before as Google is coming up blank. I really wonder if something is broken or missing from them to function properly as it seems so likely that they're supposed to be back massaging jets - they're just really terrible at their job. I have thought about buying caps with much smaller eye holes (to try to focus the stream more), but I think that may just lead to that much more water pouring out of the holes on top.

Any thoughts?

 

[Texas Splash]

Can you post some pics of the jets? Also some pics of your equipment pad so we can see all the plumbing, valves, etc.

 

[Bumpin96monte]

I don't have a pic of the pump/filter outlet on my phone, but I did have a couple old pics of the outlets in question that I marked up to try to clarify.

One of the 3 outlet pipes from the pump/filter feeds only these two nozzles. That pipe Y splits under the pool deck fairly close to the vertical tubes shown to feed each outlet. Each outlet nozzle has its own vertical tube (i.e. if you sit in front of the left nozzle, water only pours out of the left vertical pipe).

The outlets themselves are 100% identical to the regular pool return water outlets. Same size pipe / same size cap / same size hole in the cap.


Given the location, the only logical explanation I can think of is back massaging jets - its just those vertical vent tubes that baffle me. If no one on here knows what they're for, I think I'll try blocking the vents off and swapping the eye covers to a bit smaller outlet hole (to increase velocity) - maybe 1/2" or 3/8". I figure worst case, it doesn't work and I'll just permanently shut off that outlet branch again.

 

[Texas Splash]

Let's call on the assistance of @Poolbreh to see if this looks familiar. Stand by ..........

 

[Poolbreh]

Could be a water feature line for an Abandoned water slide or water fall at some point.

 

[Bumpin96monte]

Could be a water feature line for an Abandoned water slide or water fall at some point.

So you're thinking maybe those tubes extended up to something else at one point. I suppose they could've capped the outlets under water to force the water up through those vertical tubes. Thats an interesting thought as Id just assumed they were cast in flush like that.

It is on the closest spot to the house, so a slide is probably impossible in that area, but it certainly could've been a small water feature / water fall.


Since the verticals have no purpose at this point, it seems like the best bet is to plug them as step 1. All kinds of Crud likes to crawl down them and most of it ends up blown into the pool. If the jets are still fairly low flow (since they're fed by a fairly small pipe from the pump), I could play with a smaller hole eyeball cap. Worst case is they end up useless, which is what they are now anyways.

Thanks!

 

[BDY]

The outlets under water may have been for excess water overflow from the feature. So valves on feature let X amount of water in and the rest of Y water went to excess returns

 

[Turbo1Ton]

I thought I had seen a similar one before, and the upper portion was to draw air in to create a type of aerated 'spa' jet. Seeing that these are above a step/bench, it seems more plausible that this may be the case.

--Jeff

 

[1poolman1]

View attachment 495593View attachment 495594

I don't have a pic of the pump/filter outlet on my phone, but I did have a couple old pics of the outlets in question that I marked up to try to clarify.

One of the 3 outlet pipes from the pump/filter feeds only these two nozzles. That pipe Y splits under the pool deck fairly close to the vertical tubes shown to feed each outlet. Each outlet nozzle has its own vertical tube (i.e. if you sit in front of the left nozzle, water only pours out of the left vertical pipe).

The outlets themselves are 100% identical to the regular pool return water outlets. Same size pipe / same size cap / same size hole in the cap.


Given the location, the only logical explanation I can think of is back massaging jets - its just those vertical vent tubes that baffle me. If no one on here knows what they're for, I think I'll try blocking the vents off and swapping the eye covers to a bit smaller outlet hole (to increase velocity) - maybe 1/2" or 3/8". I figure worst case, it doesn't work and I'll just permanently shut off that outlet branch again.

If those are truly jets, those tubes are the air inlet that allows for the bubbles. If you block the water from exiting the jet it will be forced up that tube. They would be connected to the vertical port of a jet as in this picture (there are other forms of the same thing):

 

[Bumpin96monte]

Accidental double post

 

[Bumpin96monte]

If those are truly jets, those tubes are the air inlet that allows for the bubbles. If you block the water from exiting the jet it will be forced up that tube. They would be connected to the vertical port of a jet as in this picture (there are other forms of the same thing):

Interesting, sounds like that's got to be it. I wonder why it doesn't bubble from the jet at all then when turned on. Is there a special kind of eyeball cap needed for it to work properly?

The output from those two outlets looks no different than any of the other wall outlets (besides being much lower in pressure). The vertical tube clearly isn't blocked since the water is easily able to escape from there when resistance is encountered at the jet.

 

[1poolman1]

Interesting, sounds like that's got to be it. I wonder why it doesn't bubble from the jet at all then when turned on. Is there a special kind of eyeball cap needed for it to work properly?

The output from those two outlets looks no different than any of the other wall outlets (besides being much lower in pressure). The vertical tube clearly isn't blocked since the water is easily able to escape from there when resistance is encountered at the jet.

The orifice may be damaged or missing. If you have a VSP it may need a higher speed.

 

[Amigadude]

I have the same jets, in a similar style pool, and years ago found that the only way to get them active was to use my Jandy return valves to force less water through the other returns. The bottom line is they need more forceful water to see the (minimal, but cute) effect.

When I finally get a VSP maybe I will try again.