I had to redo the piping of a pump because the pump had to be repaired. I added a union on the pipe closest to the feed.

 

No shortage of air bubbles under the pump lid, but I don't see any water leaks.

 

Now here comes the mystery.

 

I switch off the pump, close all the feeding valves and the valve on the output, but air bubble keep arriving under the lid at a steady pace.

 

Many small bubble but every now and then a large bubble. I can clearly see the bubbles come out of the feeding pipe and not from the lid.

 

So with all feeding valves closed, the air must clearly enter somewhere between pump and valves.

 

The bubbles come so fast that in 1 hour there is visible air space under the lid, so the water must have gone somewhere.

 

I have checked the entire length of the pipe with my bare hands, and all valves, I can not find any wet spot.

 

I have replaced the lid seal already, even switched a lid from another pump, although when I look in the pump I can clearly see the bubbles enter the strainer from the pipe.

 

I just went checking again, all valves are now closed for 1 1/2 hour, and still bubbles are entering under the lid at a fast pace.

 

That's an amount of water that can't go unnoticed, so I'm really astonished that I can't find the smallest water drop on any joint.

 

As you can see from the video and image, it's quite a lot of air while running. When the pump is switched of a big bubble enters about every 2 seconds. If I close all the valves it slows down to about every 10 seconds, but it keeps coming.

 

I left pump off all night with all valves closed.

 

When I woke up the water in the strainer was right at the top of the feeding pipe. No bubbles were appearing anymore at that time.

 

The connector is at the highest level of the piping and connects to T junction that has 3 feeds.

 

I opened the lid and water in the strainer didn't drain until I opened one of the valves, which indicates the valves close properly and there was still water at the highest point of the piping, so the water in the strainer which was replaced by air must have exited the system within the pumphouse.

 

I checked all the piping again with bare hands, as specially at every joint or connection, and could not feel a wet spot anywhere.

 

 

 

I finally found a drop of water where the pipe is screwed into the pump.

 

There is plenty of Teflon tape on the thread and the fitting is screwed inside until it locked.

 

What is the solution. More or less Teflon tape, or are there fitting available in Thailand designed for the pool pump that will fit better?

Who the Foooook plumbed that mess!! ????????

This seems to an extraordinary complex plumbing system for what is a domestic pool with a salt water chlorinator. Incorrect pipe fittings and PVC grade have also been used in places. Where too many bends and elbows are in the piping, the bubbles could also be due to cavitation which over time will cause damage to the system.

2 hours ago, Bagwain said:

Who the Foooook plumbed that mess!! ????????

 

1 hour ago, SwimmingPoolsThailand said:

This seems to an extraordinary complex plumbing system for what is a domestic pool with a salt water chlorinator.

The picture may give the wrong impression because you only see part of the whole system.

 

There are 3 pumps an air blower and a chlorinator in that relatively small pump house, pool - Jacuzzi and waterfall, and every pump has access to 3 feeds.

 

There are also 5 return pipes visible in that picture, since each return has it's own feed, so all that requires a lot of pipes

 

The pipe that has cut off is the return of the Jacuzzi pump that is temporarily removed

 

In case you missed it, this thread was started to get some suggestions or advice.

 

Of course it is easier and more fun to criticize than giving advice.

 

1 hour ago, SwimmingPoolsThailand said:

Incorrect pipe fittings and PVC grade have also been used in places.

All pipes are 13.5 grade. I'm aware that some of the fittings are not 13.5 but they are on suction pipes, so i guess that is not a big issue.

1 hour ago, SwimmingPoolsThailand said:

Where too many bends and elbows are in the piping, the bubbles could also be due to cavitation which over time will cause damage to the system.

No bends were added when redoing the piping for this pump. It was done exactly the way it was, only a union was added which is visible in the picture, and there were no bubbles prior to adding the union.

 

@SwimmingPoolsThailand FYI I'm an existing customer of your company, last time I asked advice through messenger on your website the only response I got was that you didn't want to answer anonymous messages, however as an existing customer I had to login with my email before I could send you the message.

I replied to that email of yours, with the explanation that I thought you were aware of my email since I was logged in, and in the same response added my contact details.

I still never received an answer to my question, so I went elsewhere and never will be a return customer.

I would cut that mess completely out and start over

Just now, bwpage3 said:

I would cut that mess completely out and start over

Why?

 

The pool is in service for 8 years, and there has never been a problem.

 

The only problem is the air bubbles when I redid the piping for 1 pump after I had to change the gear shaft seal.

7 hours ago, Susco said:

 

@SwimmingPoolsThailand FYI I'm an existing customer of your company, last time I asked advice through messenger on your website the only response I got was that you didn't want to answer anonymous messages, however as an existing customer I had to login with my email before I could send you the message.

I replied to that email of yours, with the explanation that I thought you were aware of my email since I was logged in, and in the same response added my contact details.

I still never received an answer to my question, so I went elsewhere and never will be a return customer.

Within reasonable limits SwimmingPoolsThailand offers free technical advice whether those who request help are, or become customers or not. The company handles dozens of enquiries daily that are not concerned with the business of online sales.

 

All the company asks quite clearly is that one has the courtesy to provide a name, a broad indication of location (province), and a telephone number. This is generally the minimum required by most companies on their contact forms.

 

It is not necessary to create an account or log in in order to receive a response. Anonymous senders receive an automated reply requesting the required details. General enquiries are not handled by the same staff who process user accounts or the staff who operate the online store orders or the front-of-house showroom staff.

4 hours ago, SwimmingPoolsThailand said:

Within reasonable limits SwimmingPoolsThailand offers free technical advice whether those who request help are, or become customers or not. The company handles dozens of enquiries daily that are not concerned with the business of online sales.

 

All the company asks quite clearly is that one has the courtesy to provide a name, a broad indication of location (province), and a telephone number. This is generally the minimum required by most companies on their contact forms.

 

It is not necessary to create an account or log in in order to receive a response. Anonymous senders receive an automated reply requesting the required details. General enquiries are not handled by the same staff who process user accounts or the staff who operate the online store orders or the front-of-house showroom staff.

 

Thanks for the reply and trying to cover your own errors.

 

Did you notice that I said I HAVE an account and that I WAS logged in on your website when sending the message, so if your website login work properly you would be able to see who sent you the message and all the info you needed, otherwise what is the purpose of having an account?

 

Since I provided you with my email in the message, otherwise you would have not been able to send me that email in error, you actually had a second option to see the email was in your system already with all other details.

 

No need to reply, as this is off topic to the OP.

I don't claim any expertise but an intake of air into the system might not be evidenced by a water leak if the air was coming in to the linkages/pipework on the suction side of the pump. If it were me I would replace the union you fitted and any other pipework/valves between pool and pump involved with water supply to the pump and see if that got me anywhere. Thereafter I'd call in the pros (face-to-face) and take the flak over the spider's web less defensively than you have on the forum!

57 minutes ago, SantiSuk said:

I don't claim any expertise but an intake of air into the system might not be evidenced by a water leak if the air was coming in to the linkages/pipework on the suction side of the pump. If it were me I would replace the union you fitted and any other pipework/valves between pool and pump involved with water supply to the pump and see if that got me anywhere. Thereafter I'd call in the pros (face-to-face) and take the flak over the spider's web less defensively than you have on the forum!

What I don't understand is that I let the pump run for a minute, so pipes and strainer are full of water.

 

Right after that I close all inlet valves, as well as the valve at the inlet of the filter. There is a check valve as well on the pump outlet.

 

So that should give me a closed system. At that point air keeps seeping into the strainer, so it must come from between the valves and the pump.

 

So when I let it rest like that all night, in the morning the strainer is half empty, so that water must have gone somewhere but I can find any wet spots on the pipes

 

I notice that if I open any 1 of the 3 inlet valves the pace of the bubbles seeping increases, but I guess that is normal because then you don't have a closed system anymore.

funnily enough, I had a similar problem after working on a very old pump.... my problem most definitely was related to air coming in (being sucked in) at the inlet joint to the pump. Being a lazy <deleted>, I wrapped cling wrap and 100 mile tape around it.... problem solved.

 

that said, the amount of bubbles in your video seem insignificant and wont harm your pump or alter its performance.

 

are you losing water?

Just now, jany123 said:

funnily enough, I had a similar problem after working on a very old pump.... my problem most definitely was related to air coming in (being sucked in) at the inlet joint to the pump. Being a lazy <deleted>, I wrapped cling wrap and 100 mile tape around it.... problem solved.

 

that said, the amount of bubbles in your video seem insignificant and wont harm your pump or alter its performance.

 

are you losing water?

Not sure what you mean with that question.

 

As stated in my last post, over night the strainer will drain if i leave the valves open, and I'm afraid that when the morning cycle starts the pump will have to prime every time.

 

If I close the valves the strainer will only drain half, but I'm not supposed to close the valves after every cycle.

 

So yes I lose water if that is what you mean.

11 minutes ago, Susco said:

Not sure what you mean with that question.

 

As stated in my last post, over night the strainer will drain if i leave the valves open, and I'm afraid that when the morning cycle starts the pump will have to prime every time.

 

If I close the valves the strainer will only drain half, but I'm not supposed to close the valves after every cycle.

 

So yes I lose water if that is what you mean.

I’m assuming that’s an impeller pump, so having to prime isn’t a problem, as long as it does prime in due course (within a couple of minutes)

 

By water lose, I meant from the entire system. Are you refilling the pool more than normal? 

 

If you are  losing water from the pump inlet line, back into the pool, you might have a blocked check valve, but not be losing water from the overall system...(I have to clean my inlet check valve regularly.. secondary overflow tank vs skimmer box)

 

Anyway... the bubbles mean your sucking air from somewhere... it’s gotta be between the pool and the pump, so you need to be 100% sure your pump isn’t sucking from the newly made joint... other than those two things all I can say I good luck.

 

 

14 minutes ago, jany123 said:

Anyway... the bubbles mean your sucking air from somewhere... it’s gotta be between the pool and the pump, so you need to be 100% sure your pump isn’t sucking from the newly made joint...

I think you should read my previous posts.

 

There is no check valve on the inlet.

 

The pump get feeds from 3 sources, each source has it's own ball valve. There is a check valve and a ball valve on the outlet of the pump.

 

The real issue is that with the pump switched off and all ball valves closed air bubbles are seeping into the pump strainer constantly, draning it by half over night, but I don't see any wet spots between the pump and the closed ball valves.

????OMG how many bends have you got in all that pipe wok I have never seen such a mess . Blue pipe is so cheap can I suggest you strip the whole lot down and start again and I’m not even a plumber the least bends you have the better for the run of the water 

On 2/10/2020 at 5:18 PM, Bagwain said:

Who the Foooook plumbed that mess!! ????????

Not pretty is it! as above, those were my first thoughts!

On 2/11/2020 at 7:54 PM, Susco said:

As stated in my last post, over night the strainer will drain if i leave the valves open, and I'm afraid that when the morning cycle starts the pump will have to prime every time.

Mine does this every time I shut the pump off, it reaches a level or equilibrium and stays there, no problem if the pump has to re prime every time it starts up, its quick, cheap and painless!

Where your new union is fitted provides an ideal spot for an air pocket ,run your pump,loosen your union to confirm there is no air in this "pocket" reseal after "bleeding "the system.

I'm no expert but just to confirm: You have a presumably good valve right at the pump inlet and a similar one at the outlet. And you still get air in the strainer whether both valves are open or closed.

 

What I find strange is that you mentioned how much teflon tape you should use at the inlet connection to the pump. You should have a good coupler there with a good rubber gasket, positioned correctly at that coupler. Make sure all is clean, no nicks and No teflon needed. 

I assume you have a skimmer, If not enough water, it will take air in.

'Antifreeze' above is correct, you should have  the correct union on the pump, absolutely not a blue threaded union with teflon tape.

The correct type is in the photo - white arrow with an 'O' ring at the red arrow.  I once spent weeks trying to find an air leak in the system and this was the last place I looked. The union became tight before the 'O' ring was compressed sufficiently. Note the photo is not the inlet side.

 

Try using shaving foam around suspected joints, sometimes this will show the leak where the foam is sucked away.

 

If a glued joint is leaking you can sometimes fix it on the inlet side by applying more glue that will get sucked in but it has to be dry so only do after the pump has been running an hour or so and/or dry with a solvent such as brake cleaner or turps.

On 2/11/2020 at 8:22 PM, jany123 said:

I’m assuming that’s an impeller pump, so having to prime isn’t a problem, as long as it does prime in due course (within a couple of minutes)

If it has a mechanical seal you can destroy that pretty quickly.

Take a water hose and run water over each union on the suction side.  When you run water over the leaking connection the bubbles in the pump glass will stop or decrease, depending on the number of leaks.  Good luck.  

CLOSED (on request of OP)