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Thread: Spa Safety Drain and Jet Supply line SAFETY concern.

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    Spa Safety Drain and Jet Supply line SAFETY concern.

    We are having a pool/spa with a spillway built, on pump for pool and spa. The spa will have a separate pump for the spa jets. When the pool company plumbed it they put a split safety drain in the spa (as well as the pool but my question is about the spa drain). They also put another line from the bottom of the spa to the equipment pad to be used as a supply(suction) line. Now they plan to plumb the split safety drain as the suction or supply for the spa jet pumps and use the single supply(suction) line for spa re-circulation (plumbed to the pool/spa pump). So, when the pool is set to spa mode the water will be sucked out of the single line on the bottom and then returned via the spa return lines. Then, when the jets are turned on the water for those will be sucked out of the split safety drain and returned via the jets. This seems backwards and unsafe to me.

    My question is two fold. One, since the spa will be in spa mode whenever it's being used shouldn't the supply/suction for that come from the split/safety drain so that you have a safety drain and not a single drain in that instance. And two, should the suction supply for pump to the jet's be on another or second split/safety drain?

    It seems to me that if you use the split safety drain for spa re-circulation in spa mode then you at least have a safety drain when the jet's aren't on. At the moment the pool builder is telling me it's better to use the split safety drain for the jets because that pump pulls very hard and the other is fine as a single drain. I guess this concerns me because I have 3 daughters and between them and their friends there will be lots of long haired people swimming in this pool.


    Any input would be appreciated.

    Thanks!

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    mas985's Avatar
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    Re: Spa Safety Drain and Jet Supply line SAFETY concern.

    You need to be a little more specific on your location but I think all states have adopted the Virginia Graeme Baker Pool & Spa Safety Act and as is that setup is probably non compliant but you should probably check with the local building department. Has the pool passed inspection yet? They should have called that.

    However, if your pump has SVRS, then I think in most cases, you can get around that as long as the single port has a VGBA cover. They really should have plumbed the re-circulation lines into the same covers as the jet pump.
    Mark
    Hydraulics 101; Pump Ed 101; Pump/Pool Spreadsheets; Pump Run Time Study; DIY Acid Dosing; DIY Cover Roller
    18'x36' 20k plaster, MaxFlo SP2303VSP, Aqualogic PS8 SWCG, 420 sq-ft Cartridge, Solar, 6 jet spa, 1 HP jet pump, 400k BTU NG Heater

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    Re: Spa Safety Drain and Jet Supply line SAFETY concern.

    Thanks Mas, I am in Albuquerque NM. I have come up with the idea of eliminating the dedicated spa-jet pump and instead using the pool pump with a diverter. When we want the spa-jets on just divert a portion or all of the water from the spa return to the jets. Our pool pump is a Pentair VS and will have automation with spa side control and we cold program how much the diverter turns to jets as well as pump speed to get the jet effect we want. Is that something that would work or is there an inherent (or any) problem with doing that? I really DON'T want to use the spa suction line that is not plumed as a split safety drain and this not only seems to get around that but also seems as if it would give me more control. I am going to post this in a new post as well because I am not sure how many will see it here. Thanks!

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    mas985's Avatar
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    Re: Spa Safety Drain and Jet Supply line SAFETY concern.

    Just make sure the filter is sized appropriately for the higher flow rate. It might also be a good idea to build in a bypass which will bypass some of the water around the filter and heater when running in spa mode (actuator valve).
    Mark
    Hydraulics 101; Pump Ed 101; Pump/Pool Spreadsheets; Pump Run Time Study; DIY Acid Dosing; DIY Cover Roller
    18'x36' 20k plaster, MaxFlo SP2303VSP, Aqualogic PS8 SWCG, 420 sq-ft Cartridge, Solar, 6 jet spa, 1 HP jet pump, 400k BTU NG Heater

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    Re: Spa Safety Drain and Jet Supply line SAFETY concern.

    Thanks Mas. Sorry for the multiple postings, didn't realize this would move to the top.

    It sounds like you are saying that a diverter after the pump but before the filter and heater and then right back into the shared return line (before the diverter to the spa or pool) would do the trick. I guess in that instance anywhere from some to all of the water could bypass the Filter and heater and then play with the setting to fine tune it. I assume I would want to find the setting where the filter pressure basically stays the same as it was before the pump kicking up and the bypass valve is actuated? It would be nice if some went through the heater to keep the spa hot when the jets are on. I am very leery of using the single suction line on the bottom of the hot tub with it's own pump from a safety perspective. While the above solution may not give me optimal jet action it would be drawing from a split safety drain and I think that is much more important.

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    mas985's Avatar
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    Re: Spa Safety Drain and Jet Supply line SAFETY concern.

    Another alternative would be to plumb both the single suction line with the dual MD suction line at the pad and then split them again before the two pumps. This would effectively like have three covers. However, on each pump line after they split again, you would need a check valve to prevent recirculation through the off pump. Kind of like this:


    Code:
    -----------|
               |-----CV------- Pump
               |
               |-----CV------- Pump
    -----------|
    Mark
    Hydraulics 101; Pump Ed 101; Pump/Pool Spreadsheets; Pump Run Time Study; DIY Acid Dosing; DIY Cover Roller
    18'x36' 20k plaster, MaxFlo SP2303VSP, Aqualogic PS8 SWCG, 420 sq-ft Cartridge, Solar, 6 jet spa, 1 HP jet pump, 400k BTU NG Heater

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    Re: Spa Safety Drain and Jet Supply line SAFETY concern.

    That is a really interesting idea. The fact is the single return line is under the same cover as one of the two lines for the dual MD line (one cover has one of the pipes for the dual MD suction and the other cover has the 2nd pipe for the dual MD suction as well as the pipe for the single return line) but I would think it still should work. If the cover with the two pipes did get a vacuum seal the running pump(s) could still draw from the other open line. Also, this would give better over all flow as needed to both. I think that is a great idea! Any draw backs other than the check valves you or anyone can think of?

    Quote Originally Posted by mas985 View Post
    Another alternative would be to plumb both the single suction line with the dual MD suction line at the pad and then split them again before the two pumps. This would effectively like have three covers. However, on each pump line after they split again, you would need a check valve to prevent recirculation through the off pump. Kind of like this:


    Code:
    -----------|
               |-----CV------- Pump
               |
               |-----CV------- Pump
    -----------|

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    mas985's Avatar
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    Re: Spa Safety Drain and Jet Supply line SAFETY concern.

    The only possible issue is when the two pumps are running and one pump is a lot bigger than the other or one of the two pumps was running at lower RPM. What pumps are you planning to use?
    Mark
    Hydraulics 101; Pump Ed 101; Pump/Pool Spreadsheets; Pump Run Time Study; DIY Acid Dosing; DIY Cover Roller
    18'x36' 20k plaster, MaxFlo SP2303VSP, Aqualogic PS8 SWCG, 420 sq-ft Cartridge, Solar, 6 jet spa, 1 HP jet pump, 400k BTU NG Heater

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    Re: Spa Safety Drain and Jet Supply line SAFETY concern.

    The pump for the pool/spa is a Pentair VS (non SVRS) and the pump for the spa jets is a 2 HP Pentair.

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    Re: Spa Safety Drain and Jet Supply line SAFETY concern.

    Quote Originally Posted by Tfastle View Post
    The pump for the pool/spa is a Pentair VS (non SVRS) and the pump for the spa jets is a 2 HP Pentair.
    I should add, I suspect that when the 2hp Jet pump is running I would suspect the VS recirc pump will be very low, maybe equiv to 1/2 to 3/4hp.

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    Re: Spa Safety Drain and Jet Supply line SAFETY concern.

    Quote Originally Posted by Tfastle View Post
    I would suspect the VS recirc pump will be very low, maybe equiv to 1/2 to 3/4hp.
    Why would that be?

    If the RPM is set too low, the VS pump will not be able to fight the high suction head loss caused by the 2 HP pump and so will dead head (i.e. no flow). When the spa pump is running, there will be a minimum RPM that the VS will operate at and still provide enough flow rate for the heater and to overcome the head loss in the shared suction plumbing. Probably in the range of 2000-2500 RPM.

    Also, "Pentair" doesn't tell me much. The VS I suspect is an Intelliflo but what is the spa pump, (e.g. Whisperflo). It might make a difference.
    Mark
    Hydraulics 101; Pump Ed 101; Pump/Pool Spreadsheets; Pump Run Time Study; DIY Acid Dosing; DIY Cover Roller
    18'x36' 20k plaster, MaxFlo SP2303VSP, Aqualogic PS8 SWCG, 420 sq-ft Cartridge, Solar, 6 jet spa, 1 HP jet pump, 400k BTU NG Heater

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    Re: Spa Safety Drain and Jet Supply line SAFETY concern.

    Quote Originally Posted by mas985 View Post
    Why would that be?

    If the RPM is set too low, the VS pump will not be able to fight the high suction head loss caused by the 2 HP pump and so will dead head (i.e. no flow). When the spa pump is running, there will be a minimum RPM that the VS will operate at and still provide enough flow rate for the heater and to overcome the head loss in the shared suction plumbing. Probably in the range of 2000-2500 RPM.

    Also, "Pentair" doesn't tell me much. The VS I suspect is an Intelliflo but what is the spa pump, (e.g. Whisperflo). It might make a difference.
    The 2hp pump is Pentair 2hp SupeFlo. The pool has a 3.12 sq ft Cristal-Flo Sand Filter. I talked to Pentair support with regard to the filter and they told me running it at 1500 RPM (preset setting #2 of 4) was optimal for re-circulation and over 2500 RPM would be too high and clean very poorly. That is the only reason I thought I would be re-circulating at the lower rate.

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    mas985's Avatar
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    Re: Spa Safety Drain and Jet Supply line SAFETY concern.

    I would not use a SuperFlo for a spa jet pump. A Whisperflo is much better choice but how many spa jets are you planning?


    As for the VS, 1000 RPM is much more efficient than 1500 RPM if the skimming works well. But you will probably need to run close to 2500 RPM while the spa pump is running.
    Mark
    Hydraulics 101; Pump Ed 101; Pump/Pool Spreadsheets; Pump Run Time Study; DIY Acid Dosing; DIY Cover Roller
    18'x36' 20k plaster, MaxFlo SP2303VSP, Aqualogic PS8 SWCG, 420 sq-ft Cartridge, Solar, 6 jet spa, 1 HP jet pump, 400k BTU NG Heater

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