Stenner Pump Injection Question

1Sammy

In The Industry
Jul 20, 2017
337
Windsor, Ontario. Canada
I had the chance to get a Stenner 25 PSI pump at a really great price, so I did, lol… My question is do you think it will inject via a stenner injection / check valve adapter into my return that has 14 PSI ? Is this to close and will cause it to be slow ?
Also, in searching around I pretty much can figure out most of what I see but am wondering what Duckbills are used for ? I understand they are a seasonal replacement item but do not know where / why I would need one.
Thank you.
 

Dirk

Gold Supporter
TFP Guide
Nov 12, 2017
6,054
Central California
I'm interested in the answer to that, as I read somewhere that my injector's duckbill can be replaced with the same ones used in a Stenner. I believe the duck bill is the component of the injector that works like a check valve. It allows fluid from the pump to enter the pipe to which the injector is attached, but blocks water from running from the pipe back up to the pump. My injector is new, so I've yet to have to replace anything, but I thought it would be a good idea to have a set of the annually replaceable parts "in stock" so if/when they do fail, my system doesn't go down waiting for a part to arrive. The duckbill would be especially important, because if it failed it would mean I couldn't run my main pump.

That said, knowing Pentair as I do, I'll probably have to replace the entire injector.

Sorry, can't weigh in the PSI portion of your questions...
 

Steve_in_C

Bronze Supporter
Jul 6, 2017
360
Kinston, NC
Your 25 psi Stenner will pump fine. Put it in the circuit after the filter, heater, etc right before the water returns to the pool. The gauge pressure in your system that you are reading is the pressure in between the pump and your filter. This is not the pressure you are pumping against with the Stenner: it will be lower than that. In terms of the Duckbill, it is a check valve. In essence, it is a backup device to keep the pool water from running retrograde and filling your Stenner bleach tank. The roller compression on the pump tube should keep this from happening, but if there is a problem, the duckbill is a second backflow preventer.
 

watsowatso

Member
Sep 17, 2016
12
Houston, TX
I have a 100 psi Stenner pump setup. But, I don’t think there is any difference between the 25 psi and the 100 psi Stenner pumps, i.e. it’s the same pump. The only difference is with the setup; the 100 psi setup has an injection check valve. The replaceable duckbill goes in the check valve.

You’re probably good without the injection check valve if your return pressure is only 14 psi, and that is where you will inject (downstream of filter and heater). What’s the max pressure do you see there?
 

1Sammy

In The Industry
Jul 20, 2017
337
Windsor, Ontario. Canada
Thanks guys. Ok, so those duckbills are replacements for the check valve that is inside the stenner injector. Perfect. There size in the images threw me off. For the amount of chlorine i need each day the timer i am wiring in will turn the pump on for 7 minutes. That is open line so will re check once i get and install the injector with check valve. Appreciate the quick answers guys and will get an order off today for parts.
 

Bama Rambler

Mod Squad
TFP Expert
Bronze Supporter
LifeTime Supporter
Jun 22, 2009
24,094
SouthWest Alabama
Just for some clarification.

All the Stenner pump mechanical parts are the same within the same class. There are two differences between the 25 psi and the 100 psi models. One is the check valve/duckbill difference and the other is there are a few pump tube numbers that aren't rated for 100 PSI.
 

Dirk

Gold Supporter
TFP Guide
Nov 12, 2017
6,054
Central California
Sorry, Just seeing this message. Yes these are the duckbills. Since my post, I have talked with Stenner pumps. They tell me that you do not have to have duckbills for the lower pressure (25psi) applications. It's just a backup and only required with higher pressures.
I've been assuming that the pump itself is the primary check between pool water and tank. But mine is an acid injector, so pressure or no, I like the extra backup, acid-inta-wata and all...
 

1Sammy

In The Industry
Jul 20, 2017
337
Windsor, Ontario. Canada
I've been assuming that the pump itself is the primary check between pool water and tank. But mine is an acid injector, so pressure or no, I like the extra backup, acid-inta-wata and all...
I say a good move on the check valve. I did not use the injector with the duck bill ( check valve ) as i purchased the kit for my pump and because it was 25 PSI Stenner says no need. What i see as what can be an issue with out it is this. They say to run a return back to the tank which is a good idea if the tube should pop a leak. BUT, with no check valve that tank will want to be as large as your pool, lol, as the main pool pump will push back to the stenner and into the return line and to your storage tank, not good. Getting these parts across the border is much much $ so i will wait till i need something else and i will get and add the injector with the check valve.
My pump is the 85GPD and i need just 3.5 minutes to add my daily dose of chlorine. Because my timer can not do half minutes i will drop the speed down from wide open 10 a little and set the on time to 4 minutes.
As mentioned in an above post the pressure on the pool return line is under the pressure on the head gauge, you are correct. I checked this with a gauge in the line where i put the injector and it is 7 PSI.
 

Dirk

Gold Supporter
TFP Guide
Nov 12, 2017
6,054
Central California
I say a good move on the check valve. I did not use the injector with the duck bill ( check valve ) as i purchased the kit for my pump and because it was 25 PSI Stenner says no need. What i see as what can be an issue with out it is this. They say to run a return back to the tank which is a good idea if the tube should pop a leak. BUT, with no check valve that tank will want to be as large as your pool, lol, as the main pool pump will push back to the stenner and into the return line and to your storage tank, not good. Getting these parts across the border is much much $ so i will wait till i need something else and i will get and add the injector with the check valve.
My pump is the 85GPD and i need just 3.5 minutes to add my daily dose of chlorine. Because my timer can not do half minutes i will drop the speed down from wide open 10 a little and set the on time to 4 minutes.
As mentioned in an above post the pressure on the pool return line is under the pressure on the head gauge, you are correct. I checked this with a gauge in the line where i put the injector and it is 7 PSI.
Yes, in addition to the ramifications of water being pumped into your chemical, there is the possibility of emptying your pool or running your skimmer dry. Of course it would happen on your week away, right?

Did you consider, or do you have the capability of, timing your dispensing in smaller doses many times a day? One of the advantages of SWG over manual dosing is the constant dispensing of chlorine, at least during the SWG's active run. Mine is seven hours long, during the day. So for most of the day my FC is relatively level. I believe that is the main reason SWG pools can run a slightly lower FC target, because there is no big spike of FC that then proceeds to descend to a low point, just before the next daily spike. So if you pump all your chlorine into your pool in one 3.5 minute session, you are in essence adding chlorine manual-style, and perhaps not reaping one of the best benefits of chemical-addition automation.

Can you set your timer to dispense for 1 minute, four times a day?
 

Dirk

Gold Supporter
TFP Guide
Nov 12, 2017
6,054
Central California
Another vote for the duck: one of the comforts of my plumbing is the heavy-duty equipment connected with nice, thick PVC, all welded together with glue. My injector system introduced a dinky little 1/4" tube, connected with push fittings! Without the duckbill check, that tubing and those fittings would become part of the pool's main plumbing system. No thanks. It's not just about what the injector pump can withstand, but also the line between it and your main plumbing. And in my case, that line is subjected 24/7 to 31% MA!
 

Steve_in_C

Bronze Supporter
Jul 6, 2017
360
Kinston, NC
It's certainly OK to have the duckbill as an extra backup. I have one. It came with my Stenner set up and I haven't taken it out although Stenner Pump technical support says I don't need it. They don't really cost much and you can replace one in 30 seconds. You just unscrew the injector pop the old one out and new on in. Thats all there is to it. The pump tube is not much harder to replace and there are YouTube videos showing you how. The Aquasport grease is a little pricey. I bought 1 tube and it will likely last the life of the pump.
 

1Sammy

In The Industry
Jul 20, 2017
337
Windsor, Ontario. Canada
Another vote for the duck: one of the comforts of my plumbing is the heavy-duty equipment connected with nice, thick PVC, all welded together with glue. My injector system introduced a dinky little 1/4" tube, connected with push fittings! Without the duckbill check, that tubing and those fittings would become part of the pool's main plumbing system. No thanks. It's not just about what the injector pump can withstand, but also the line between it and your main plumbing. And in my case, that line is subjected 24/7 to 31% MA!
For sure. On my list to be added asap as right now this is weak point.

- - - Updated - - -

It's certainly OK to have the duckbill as an extra backup. I have one. It came with my Stenner set up and I haven't taken it out although Stenner Pump technical support says I don't need it. They don't really cost much and you can replace one in 30 seconds. You just unscrew the injector pop the old one out and new on in. Thats all there is to it. The pump tube is not much harder to replace and there are YouTube videos showing you how. The Aquasport grease is a little pricey. I bought 1 tube and it will likely last the life of the pump.
Why would those duck bills need to be replaced? New to this injection chlorine so do not know what to expect to see in the lines and plumbing around / near this new set up.
 

1Sammy

In The Industry
Jul 20, 2017
337
Windsor, Ontario. Canada
Yes, in addition to the ramifications of water being pumped into your chemical, there is the possibility of emptying your pool or running your skimmer dry. Of course it would happen on your week away, right?

Did you consider, or do you have the capability of, timing your dispensing in smaller doses many times a day? One of the advantages of SWG over manual dosing is the constant dispensing of chlorine, at least during the SWG's active run. Mine is seven hours long, during the day. So for most of the day my FC is relatively level. I believe that is the main reason SWG pools can run a slightly lower FC target, because there is no big spike of FC that then proceeds to descend to a low point, just before the next daily spike. So if you pump all your chlorine into your pool in one 3.5 minute session, you are in essence adding chlorine manual-style, and perhaps not reaping one of the best benefits of chemical-addition automation.

Can you set your timer to dispense for 1 minute, four times a day?
Interesting you brought this up as something i have thought about. First, yes i can have main pump and injection come on by the minute at any time up to 17 times a day.
Now the big question, lol... I think, and i mean think as no proof yet, but i feel the other way around as you do Dirk on the injection. For 40 years i have been bending over to add chlorine at a return. All at once in a quart container that i draw off from my storage tank. I "feel" that as sort of a shock treatment ! Now before you guys jump on me i know SLAM is your word but the first letter of SLAM stands for shock, lol. Anyway,,,, been doing that for years and very little issues. Believe it or not, 32 oz a day. Never do that once a week pool store shock thing. Solar blanket on full time except when someone in the pool. I am now thinking that because i got bored / lazy and read on here about these injector pumps that wow i need to do that and now in doing so i bet ya that i will have to up my chlorine level because i have lost that instant hard hit from hand pouring. I'll know in a week or so. We have acid rain in my neck of the woods so i won't be able to play with another pump for acid as you do, darn lol. Thanks.
 

Dirk

Gold Supporter
TFP Guide
Nov 12, 2017
6,054
Central California
Why would those duck bills need to be replaced? New to this injection chlorine so do not know what to expect to see in the lines and plumbing around / near this new set up.
I'll have to replace several components in my system, annually, because of the acid. Maybe the chlorine causes similar issues for an injector system, and so regular replacement maintenance will be something for you, too. I got my "replacement advice" from my unit's owner manual. Perhaps Stenner support can offer you some insight about this issue, as it relates to chlorine. Other TFP Stenner users would know, too.
 

Steve_in_C

Bronze Supporter
Jul 6, 2017
360
Kinston, NC
Not sure if annual replacement is necessary for chlorine. Especially when you don't need it in the first place. Many times plastics are softened by chemicals. This may be why there is a recommendation to replace them. Either way, it's easy and cheap if you choose to have one or replace one.