Sealing threaded plumbing on circulating pump

[rhostam]

Hello there,

I am building my water mixing station and the pump I ordered to do this said it included fittings for certain applications.

Since I was planning on using 1” schedule 80 for the plumbing attaching to the pump, I figure I’d leave the union fitting they had preinstalled.

After tightening all fittings I ran a water test and found that the provided union fitting leaks.

Question:

What is the best way to plumb this?

I used tape and wound a few times and tightened the fitting. However, I read that tape was meant for thread metal connections.

I have seen recent discussions about sealing threaded connections, however, I’m not sure those solutions applied to this situation since any glue would keep the fitting permanently attached to the pump.

Any advice would be most appreciated as I feel like I am missing a gasket or something, otherwise.

The pump in the photo is a [VarioS-2 Controllable DC Pump (792 GPH) - Reef Octopus].

 

[rhostam]

I just found a gasket in a folden section of the box and while it isn’t clear where this goes, I am going to try something. It may be for the barbed fitting they provided.

(it was a bust - looks like it is for the barbed fitting)

 

[mrlavalamp]

Is the union itself leaking or the threads where the union mates to the pump?

Unions can be finnicky sometimes and you might need to get some mechanical advantage to get it tight enough (the limited knurling on the "nut" makes it hard to hand tighten them enough). Dont go too hard though or its likely to crack.

For sealing plastic threads I use this stuff: https://www.homedepot.com/p/RectorSeal-T-Plus-2-in-4-oz-Teflon-Pipe-Thread-Sealant-23631/100201204

 

[rhostam]

Is the union itself leaking or the threads where the union mates to the pump?

Unions can be finnicky sometimes and you might need to get some mechanical advantage to get it tight enough (the limited knurling on the "nut" makes it hard to hand tighten them enough). Dont go too hard though or its likely to crack.

For sealing plastic threads I use this stuff: https://www.homedepot.com/p/RectorSeal-T-Plus-2-in-4-oz-Teflon-Pipe-Thread-Sealant-23631/100201204

Great question: the leak is coming from the union threads to the pumps threads and not the union itself.

I’ll take a look. Thanks!

 

[AlexG]

Looking at the picture it looks like the threaded union fitting onto the pump is where it is leaking. If this is the case Teflon tape can work but often times it can still leak. Teflon sealant pasts works but its messy and can get into your tank water. I use standard silicone one for my threaded PVC connections to seal them. Silicone one will need 12-24hrs to cure once the fittings are put together but its a cheap solution that has little mess and works better than Teflon in my experience. Silicone one can also be easily removed from the PVC if the fittings need to come apart for maintenance since it cannot stick to PVC. If you use silicone only use silicone one without anti-mold additives as those can be toxic to marine life.

 

[Saltyreef]

Agreed with @mrlavalamp
get yourself some sealant meant for plastic threads
You already found out the hard way tape is meant for metal threads.

 

[DrZoidburg]

Go a extra couple tape winds? Only looks like a small leak. Where the cracks usually happen are abs bulkheads, and pvc adapters. I don't very often see male adapters crack. Nor ever seen a pump crack from ptfe.

 

[RobB'z Reef]

Hello there,

I am building my water mixing station and the pump I ordered to do this said it included fittings for certain applications.

Since I was planning on using 1” schedule 80 for the plumbing attaching to the pump, I figure I’d leave the union fitting they had preinstalled.

After tightening all fittings I ran a water test and found that the provided union fitting leaks.

Question:

What is the best way to plumb this?

I used tape and wound a few times and tightened the fitting. However, I read that tape was meant for thread metal connections.

I have seen recent discussions about sealing threaded connections, however, I’m not sure those solutions applied to this situation since any glue would keep the fitting permanently attached to the pump.

Any advice would be most appreciated as I feel like I am missing a gasket or something, otherwise.

The pump in the photo is a [VarioS-2 Controllable DC Pump (792 GPH) - Reef Octopus].

this is classic in those varios pumps... i see this often. Best to use is a quality plumbers paste, just locate it neatly on the external threads keeping it below the first thread, don't overdo it as you're trying to avoid having it flow back over the top. It shouldn't but... if you are really worried about it the next best option is a good plumbers tape, just a couple wraps and that will also work. I've done both with equal success. That threaded portion is a pretty bad design on their part for the application.

 

[Flameback Pair]

Is the union itself leaking or the threads where the union mates to the pump?

Unions can be finnicky sometimes and you might need to get some mechanical advantage to get it tight enough (the limited knurling on the "nut" makes it hard to hand tighten them enough). Dont go too hard though or its likely to crack.

For sealing plastic threads I use this stuff: https://www.homedepot.com/p/RectorSeal-T-Plus-2-in-4-oz-Teflon-Pipe-Thread-Sealant-23631/100201204

@rhostam defininely use Rector Seal #5. It’s the only pipe paste without lead. Reef safe. Don’t use silicone. It WILL stick to PVC. I first heard of Rector Seal on Neptune Systems forum highly recommended by the moderator for the threads on Apex flow sensors. Also apply o-ring lubricant to o-rings to seal. Molycote 111 from BRS.

 

[DrZoidburg]

No it doesn't stick. It does but can easily peel it off. I wouldn't recommend it for this job though.

 

[Flameback Pair]

No it doesn't stick. It does but can easily peel it off. I wouldn't recommend it for this job though.

You say it doesn’t then you say it does. Which is it. From my experience silicone is very difficult to remove from anything and takes a razor blade. Silicone inside pipe threads is very difficult to remove. Razor won’t help.

 

[Little c big D]

You say it doesn’t then you say it does. Which is it. From my experience silicone is very difficult to remove from anything and takes a razor blade. Silicone inside pipe threads is very difficult to remove. Razor won’t help.

You're right it can be a PITA but silicon will come off. Its much better to use the reef safe pipe dope you suggested though.. Silicon could fail in this application and the annoyance of peeling it seems unworth the effort..

 

[Flameback Pair]

@rhostam when you use rector seal, douse it liberally on the male AND female threads it should run out of the joint when you screw it together. Don’t worry about this it is safe for your skin and washes out of clothes. Just wipe up the excess that runs out of the joint with a rag or paper towel. It stays soft for a few days and might continue to seep out so wipe that up. When it sets it has the consistency of tar so the threaded parts can be unscrewed but it takes some force.

 

[ying yang]

Im a plumber of 20 plus years and never heard until i started reefing that teflon tape only for metal fittings.i have been shown by a fellow reefer where american plastics association or something like this says no teflon tape on plastic fittings but here in england when commercial plumber and domestic plumbing and heating engineer i often used ptfe tape on plastic fittings and aslong as dont over tighten i never really had a problem.hand tight then give half - 3/4 turn on non pressurised systems.not sure if because saltwater or what ( doubt it) or maybe our regulations in england different.
On any union or piece you may have to remove you dont want use anything which will permantly seal as said above defeats the whole point.
Using silicone idk as never bodged a job up doing this way lol.
Sometimes i have bought a full rubber washer and cut my own whole in it and made my own washer/gasket.anyway just thought id share so as you where ^_^

 

[Flameback Pair]

 

[Flameback Pair]

Im a plumber of 20 plus years and never heard until i started reefing that teflon tape only for metal fittings.i have been shown by a fellow reefer where american plastics association or something like this says no teflon tape on plastic fittings but here in england when commercial plumber and domestic plumbing and heating engineer i often used ptfe tape on plastic fittings and aslong as dont over tighten i never really had a problem.hand tight then give half - 3/4 turn on non pressurised systems.not sure if because saltwater or what ( doubt it) or maybe our regulations in england different.
On any union or piece you may have to remove you dont want use anything which will permantly seal as said above defeats the whole point.
Using silicone idk as never bodged a job up doing this way lol.
Sometimes i have bought a full rubber washer and cut my own whole in it and made my own washer/gasket.anyway just thought id share so as you where ^_^

@rhostam there’s a right way to put on Teflon tape. Google YouTube for a video on it.

 

[ying yang]

I only used gas ptfe for gas fittings but for normal plumbing fittings we always used to prefer the threaded ptfe.its much thinner and less chance to put to much on.
But normal ptfe tape is wrap around clockwise direction in direction the thread goes and wrap around 2- 2.5 times is general rule of thumb but if using it on plastic fittings then need be extra careful not to over tighten as can crack fittings easy but once know how to do it its a doddle tbh,if put to much ptfe on this can make it easier to crack fitting as asserting to much force on fitting.

 

[DrZoidburg]

@powers2001 If you want to get technical it has to do with coefficients of frictions. It does stick but it is not a chemical bond.

 

[Flameback Pair]

I only used gas ptfe for gas fittings but for normal plumbing fittings we always used to prefer the threaded ptfe.its much thinner and less chance to put to much on.
But normal ptfe tape is wrap around clockwise direction in direction the thread goes and wrap around 2- 2.5 times is general rule of thumb but if using it on plastic fittings then need be extra careful not to over tighten as can crack fittings easy but once know how to do it its a doddle tbh,if put to much ptfe on this can make it easier to crack fitting as asserting to much force on fitting.

@rhostam this is correct but he forgot to mention not to get tape above first thread or it could snag on other threads and bunch up causing leaks. I use tape for jobs where there is little play between the two threaded fittings because it only takes a few wraps. If it’s loose and would take a lot of wraps I use rector seal instead.

 

[ying yang]

@rhostam this is correct but he forgot to mention not to get tape above first thread or it could snag on other threads and bunch up causing leaks. I use tape for jobs where there is little play between the two threaded fittings because it only takes a few wraps. If it’s loose and would take a lot of wraps I use rector seal instead.

When we do something often it becomes second nature and just do without thinking and when try to explain,we ( i) try to simply it thinking all should know some off it.
But i remember when first training i didnt even know what a trv was or even name off fittings as didnt need to know i guess.^_^

So yeah tape or thread must be tight on fitting and watch doesnt snag,
For such a simple procudure now im writing it down there sure is alot actions or things to make sure do or dont do,