Cracked Half Union on SWCG Cell

[Kit]

A few days ago I removed the "dummy cell" & replaced it with the SWCG. The dummy cell had been in place for the past 6 months. No issues whatsoever. When I put in the SWCG, I discovered a leak through the tightening ring on one of the half unions. I assumed that the baffles in the SWCG was partially restricting the water flow and, thus. forcing the water through the crack in the half union.

Therefore, I have 2 questions:
1. Regardless of the fact that there is a small crack in the half union, I would assume that if the 0-rings on the half unions properly sealed against the SWCG cell, there should be no leaks in the tightening ring whatsoever. Does this make sense? (I might add that I followed up with a coating of PVC joint compound on the threads of the SWCG, but the leak still occurred).

2. I assume that the cracked half union will have to be replaced. The problem, however, is that when I cut off the cracked half union, there is not enough room in the incoming & outgoing PVC pipes to glue in a straight butt coupler and leave enough room for the SWCG cell. Is there a creative way to resolve is issue?

Thank you so much for your help.





Kit

 

[Griswald]

You can buy a split union nut, it's 2 half's of the nut that you place over the pipe and screw together. Dirt cheap also.

 

[Homebrewale]

Here is a split union I used.

Amazon.com

 

[ajw22]

Use a Hub Saver to ream put the elbow and reconnect a pipe to it. Read PVC Repair - Further Reading

 

[Kit]

Griswald & Homebrewale: Brilliant! Didn't know the product existed.

AJW22: I recently became aware of the Hub Saver option. For the ease of the split union nut, I think I will see if that resolve the problem first. Nevertheless, thank you.

BTW, one other question: Can the o-rings in the half unions be replaced?

 

[1poolman1]

Griswald & Homebrewale: Brilliant! Didn't know the product existed.

AJW22: I recently became aware of the Hub Saver option. For the ease of the split union nut, I think I will see if that resolve the problem first. Nevertheless, thank you.

BTW, one other question: Can the o-rings in the half unions be replaced?

Pentair chlorinator? Here's one example:

Pentair IntelliChlor iChlor Salt Chlorinators Union O-ring 521147 – 2 Pack – PoolAqua.com

poolaqua.com

 

[Kit]

Thank you, 1poolman1. Yes, I do have a Pentair Intellichlor. And I ordered the o-rings.

 

[Dirk]

Another consideration...

While there is debate about the necessity of this on the forum, Pentair IntelliChlor (IC) instructions are clear: there is supposed to be 12-18" of straight pipe before a Pentair IntelliChlor. I personally think this is a good thing, as it might provide better, undisturbed flow over the IC's flow switch, which could therhetically allow you to run at lower RPMs, which should save you some energy cost.

Not only is that missing from your plumbing, but it looks like the IC union is very close to the output of your heater. Which might explain why that part fatigued and cracked the way it did. It's supposed to be at least 3' away from a heater.

You might consider replumbing the IC to both get you the 18" and the 3'.

This diagram shows a bypass in the plumbing of the IC, but you wouldn't need that. And it's not drawn well, as it doesn't show the recommended 18" run. Pentair also recommends installing the IC vertically, but that idea gets even less support from the forum, and I don't personally put much stock in it.

 

[Kit]

Dirk: Your point is well-taken. And had I did the plumbing, I would have done it differently. But the plumbing has been in place for 9 years with no issues. For me, re-plumbing will be a last resort. Thank you for your input.

 

[Kit]

Can anyone verify which specific split union nut will fit properly on a Pentair Intellichlor SWCG? I ask because there are a number of people who claim that either the replacement nut does not fit or that the thread pitch doesn't match that of the Intellichlor. Hopefully someone who replaced the nut on an Intellichlor will respond. Again, thank you so much!

 

[Dirk]

the plumbing has been in place for 9 years with no issues

Uh, well, that's not exactly accurate, now is it? You might not see any advantage to the 18" run, but your IC is too close to your heater. Perhaps next time the fitting fails you'll again be lucky enough to be standing nearby.

Anyway, I don't know what a "split union nut" is, but I do know the threads on a Pentair IntelliChlor are proprietary (or at least non-standard), as you can't go to Lowes and build a dummy cell out of PVC and off-the-shelf fittings that will mate to the IntelliChlor unions.

Hopefully someone else here will know what the threads are.

 

[Dirk]

Here's some info:

Simple Fix for a Cracked Union Nut on a Pentair Salt Cell

I’ve found the information on TFP very helpful, but didn’t see the need to participate in the forum until now. When I put the blank in place of the Pentair IC40 salt cell for this winter, one of the Union nuts cracked. Everything that I found in the forum, on-line and talking to my local pool...

www.troublefreepool.com

 

[Homebrewale]

There are probably several reasons why a union will crack. I do know why mine cracked one time. I had this bad habit when I first started opening and closing a pool to overtighten unions. After getting it hand tight, I would add about another quarter turn with a strap wrench. Since then, the strap wrench stays in the tool box.

 

[Kit]

Homebrewale: I suspect that I was guilty of over-tightening as well when the Intellichlor was installed years ago. However, since then I too have changed my evil ways.

Quick question: On the split union nut that you used, did the threads on the nut match the threads on the Intellichlor SWCG? Some people have said that the Intellichlor threads are proprietary. Thank you for your help.

 

[Griswald]

If you lived in the south, where the sun literally destroys all plastic given time, you wouldn't even be worrying about over tightening. My first nut cracked and a year later, the second one just sort of powdered away. You could pick pieces of the outside off with a thumbnail.

Both are fixed with a half union nut.

 

[Kit]

I'm sold on the split union nut. I just need to be certain that the thread pitch is the same as on the Pentair Intellichlor SWCG.

 

[Homebrewale]

Homebrewale: I suspect that I was guilty of over-tightening as well when the Intellichlor was installed years ago. However, since then I too have changed my evil ways.

Quick question: On the split union nut that you used, did the threads on the nut match the threads on the Intellichlor SWCG? Some people have said that the Intellichlor threads are proprietary. Thank you for your help.

I don't know. The description for the split union says both Hayward and Pentair. On that pool, I had a Hayward SWG and it fit perfectly.

Considering the price of the split union, what do you have to lose to try it? If it doesn't fit, it's just a small loss or use the return policy of the store.

 

[Kit]

Thank you. I planned to give it a try.

 

[JamesW]

Fits Pentair and Hayward Salt Cells and some hot tub pumps. | Mikeys Quick Coupler

FYI- The threads on the brand NEW IC40's have changed! Sometime during 2023 there was a change. MY Mold has not changed since I built it in 2019. So if your Chlorinator is a 2023 or newer, this may not fit. We are working on this!!!! Should have another one out soon. This coupling...

www.mikeysquickcoupler.com

 

[Kit]

Thank you. I planned to give it a try.

James W: thanks for the info. I erred when I said I had a IC40. It’s an IC20. It was purchased in 2016. So hopefully the threads on the split nut will fit.