Ball valve to slow down flow rate of spa spillover

[mas985]

I actually need three settings:
pool - suction from pool and 100% return to pool
spa - suction from spa and 100% return to spa - my heater is set to come on when I put it in spa mode
spillover - suction from pool and 50% return to spa/50%return to pool - this will allow me to get a gentler cascade for a waterfall

As Bruce pointed out, the actuator on the return side in what is now pool mode would be changed such that pool mode would not shut off the spa return completely. However, this also means that you do not have a pool only mode but do you really need that? You will still have these three modes:

Spa only (Spa suction, Spa return)
Pool with low rate spillover (Pool Suction, Cammed Pool Return - Spa Partially On)
High rate spillover (Pool Suction, Spa Return)

Your current setup only allows for two different return paths. What you are really talking about is three different return paths and four modes:

Spa Only (Spa Suction, Spa Return)
Pool Only (Pool Suction, Pool Return)
Spillover (Pool Suction, Spa Return)
Low Spillover (Pool Suction, Pool and Spa Return)

You can accomplish this with a bypass pipe that connects the pool return to the spa return (before check valve) with a valve and actuator plus another valve control port on the PS-8, assuming you want automatic control. So in pool or spa mode, the second valve is opened and water diverted to other port.

 

[Ranger987]

Adjust the cam on ONLY the return side actuator so that it will not shut off the spa returns completely when in POOL mode, and will give you the desired spillover to keep the spa circulated while in POOL mode. If you cam it properly, you will not affect correct operation in SPA mode, where you need 100% to/from the spa for heating. When in POOL mode, you'll pull 100% from pool, thru filter then spllit 75% to pool 25% to spa - or desired ratio. When you switch to SPA mode, you'll have 100% spa suction and 100% spa return, as you should. No need for a bypass line. This is extremely common and if the return side actuator only is cammed properly, you'll get what you're looking for with no extra expense.

 

[waste]

Adjust the cam on ONLY the return side actuator so that it will not shut off the spa returns completely when in POOL mode, and will give you the desired spillover to keep the spa circulated while in POOL mode. If you cam it properly, you will not affect correct operation in SPA mode, where you need 100% to/from the spa for heating. When in POOL mode, you'll pull 100% from pool, thru filter then spllit 75% to pool 25% to spa - or desired ratio. When you switch to SPA mode, you'll have 100% spa suction and 100% spa return, as you should. No need for a bypass line. This is extremely common and if the return side actuator only is cammed properly, you'll get what you're looking for with no extra expense.

This is EXACTLY the way I used to set them up

However, because of the way the actuators are made, you can't stop the spillover function

If you throw another valve into the equation (that doesn't have an actuator) you run the risk of forgetting to reopen it and 'messing things up' And, the unit only supports 4 actuated valves (which was a MAJOR problem in the pools we install which had 2 -4 suctions, and 5+ returns/ jets ).

This has been a source of frustration for me for the past 6 years :x I'd love to talk with the experts here about how to design a better actuator, which would be able to stop in more than 2 positions (my old partner and I spent many an hour and a lot of $$ at the bar trying to figure out how to do this )

 

[Ranger987]

I agree that we need better actuators, they could probably be designed, but will cost more, so only you and I will buy them. :lol: My experience is that most folks don't need to stop the spillover very often, and when I did, I just removed the actuator temporarily & made manual adjustments. No magic bullets here.

 

[Ohm_Boy]

(my old partner and I spent many an hour and a lot of $$ at the bar trying to figure out how to do this )

So... just drilling a hole and mounting a solenoid to pop into/out of the cam space to add another stop point is out, eh?

 

[waste]

About as far as we made it was to have metal bands, 1 in the valve housing and one on the valve stem that would be able to know where the gate was through all 360*. If we could have figured out how to make the sensor know where the gate is, at any given point, all you need is the software to enable it to stop in multiple positions, for the various functions :|

However, neither of us had a college degree in anything :lol: So the practicability of having a small strip of (say gold) above the gate, so the differential could be measured as it cruised around and the motor would know to stop at different places, depending on which function was selected, never materialized

Ah, well - there went our $ million idea (I think the concept is sound, but don't know how to 'make it a reality' :x )

If any of y'all can take this and run with it, we'll all split the proceeds :-D

 

[Guest]

I guess I am at a loss here... If this was plumbed right the first time, it would have cost an additional $50.00 and the problem would be solved. Then he could adjust his spillover however he wanted it...

 

[CombatYoga]

I understand the point about fiddling with the actuator on the return side.

I'm running my circulation pump 8 hours per day right now, and I run it 10-12 hours per day in the summer.
My only worry is that the pH in my water would rise quickly as some level of spa spillover (and hence aeration) would be happening
whenever in POOL mode.

Is that a legitimate concern? Would my acid use go up noticeably?

Thanks for a great discussion!

SF

 

[mas985]

There are trade-offs with everything. PH might go up a bit but if you correct for it with acid, then eventually, the TA may come down thereby reducing the amount the PH will rise. Self correcting in some ways. However, if you have high TA fill water, then it may be an ongoing issue.

But if you reduce the amount of waterfall, it could end up being a wash. With the cam adjustment, it is fairly easy to experiment without cost so why not try it?

 

[Ohm_Boy]

About as far as we made it was to have metal bands, 1 in the valve housing and one on the valve stem that would be able to know where the gate was through all 360*. If we could have figured out how to make the sensor know where the gate is, at any given point, all you need is the software to enable it to stop in multiple positions, for the various functions :|
However, neither of us had a college degree in anything :lol: So the practicability of having a small strip of (say gold) above the gate, so the differential could be measured as it cruised around and the motor would know to stop at different places, depending on which function was selected, never materialized
Ah, well - there went our $ million idea (I think the concept is sound, but don't know how to 'make it a reality' :x )
If any of y'all can take this and run with it, we'll all split the proceeds :-D

So... start with a gear on the valve stem, and a motor/worm to drive it. There should be a suitable shaft encoder which could give positional feedback on where the gear (and therefore the gate) is at any given point, and that should provide the 'smarts' with enough info to run the motor to a new position. A stepper motor would give finer control. In fact, with a stepper, you *could* run it open-loop (no position feedback) and just position to some pre-set number of steps per position. If you do open loop, though, you really some way to reset to a known place, generally 'brute-force' positioning to a home location.

 

[mas985]

Why not just use a simple time delay relay? After so much time delay (less than full movement), the circuit opens one the drive wires shutting off the motor. The time required to move from one position to the next is fairly predictable and repeatable. Also, it could be wired with a bypass diode to affect only one direction so when the controller flips to the reverse setting, the cam would work normally.

Something like this might work.

 

[Ohm_Boy]

Could an automotive Throttle Position Sensor (TPS) be fitted to one of these valves?

 

[taekwondodo]

One disadvantage - not a very big one - to using just the actuator "tuned" to the spillover rate from the spa to the pool when in pool mode.
Should work fine in Pool Mode, Spa Mode, and Spa Fill mode, but in Spa Drain the valve won't close all of the way and it will take longer to drain the spa.