I had to replace a pump sweep ell that was leaking. This transitioned to flex pvc. The diameter of the flex pvc seems to be less than the sch 40 slip coupling I'm using. After a few minutes I could remove the coupling with little effort. Used pvc cleaner on the flex and primer on the coupling. Oatey all purpose pvc cement.
Flexible pvc diameter
- Thread starter mikewhits
- Start date
Flex has the same diameter as rigid pvc, but you should not use cleaner or primer on the flex as it softens the material and causes a blow out of the glue joint. It also will not form the fast bond that rigid does and must be allowed to fully cure before being put under pressure or roughly handled. If it seems loose in a dry fit of the fitting apply a coat of cement to the pipe and allow it to skin over before applying the final coat to pipe and fitting and making the joint.
When glueing to any old pipe it is vital that surfaces be clean and dry (unless using a wet use cement).
My preferred cement is Christy's red hot blue glue.
When glueing to any old pipe it is vital that surfaces be clean and dry (unless using a wet use cement).
My preferred cement is Christy's red hot blue glue.
Thank you for your reply. I measured the o.d. of the flex with a caliper seems to be 58 mm. The o.d. of the rigid pvc I'd 60 mm. Is this an acceptable allowance for a slip joint to seal?
That’s strange, I used flex on a piece and it was very snug. Maybe got a bad piece or wrong kind?
Actually, it is the original piping on the spa, I'm just tying back into it after cutting the connection out that I had to replace. This is off the discharge side of the pump.
That should be mo problem, just put a coat of glue on it and let it set for 5 minutes as described. Then give it at least 4 hours before you mess with it.
And like you said earlier have to use primer. I have done regular PVC without primer and it worked but when I did flexible PVC without it it leaked both times
I said DO NOT use primer on flex. This came from a pvc manufacturer I contacted after having multiple repairs blow apart. It can break down the surface of the flex and cause it to peel off after it is glued, thus blow apart the glue joint. Pipe must be clean but just use soap and water and wipe dry, or lightly sand.
It may depend on the exact chemical formula of the pvc. I have come to suspect that they are not all created equal.
I still remember the conversation some 25 years ago. There was no internet as we know it today and little industry training. I had been an electrician before so had no experience with flex but plenty with pvc and had several spa plumbing repairs blow apart at my first job in the business. So I called the flex manufacturer. Had to leave a message and wait a few days for the guy to call, but he did. I explained my situation, he said "Are you using primer on the flex?", I said "Of course.", he said "Well DON'T!", and hung up the phone.
Ahh, the good old days...
So I have not used primer on flex since. And I swear by Christys.
tchristy.com
I still remember the conversation some 25 years ago. There was no internet as we know it today and little industry training. I had been an electrician before so had no experience with flex but plenty with pvc and had several spa plumbing repairs blow apart at my first job in the business. So I called the flex manufacturer. Had to leave a message and wait a few days for the guy to call, but he did. I explained my situation, he said "Are you using primer on the flex?", I said "Of course.", he said "Well DON'T!", and hung up the phone.
Ahh, the good old days...
So I have not used primer on flex since. And I swear by Christys.
Red Hot Blue Glue - Low VOC - Christy's
Contractor preferred, premium formulation Medium body, very fast set All classes and Schedules thru 6″ diameter interference fit (Schedule 80 through 4″) Can be used without primer if local codes permit for non-pressure systems up to 6″ and pressure systems below 4″ Blue in color
tchristy.com
The coupling should be relatively snug when dry fit. If not, something is off. Are you sure that it's flex pvc and not hose or black poly pipe?
In my opinion, cleaner can be used.
Primer is more aggressive and results in more softening of the pipe.
Old flex can deteriorate to the point where it's basically useless to try to glue a fitting.
When gluing flex, you should hold the fitting securely on the pipe for at least 60 seconds and then give it at least 12 hours to dry.
www.oatey.com
In my opinion, cleaner can be used.
Primer is more aggressive and results in more softening of the pipe.
Old flex can deteriorate to the point where it's basically useless to try to glue a fitting.
When gluing flex, you should hold the fitting securely on the pipe for at least 60 seconds and then give it at least 12 hours to dry.
Oatey® PVC Flexible Medium Clear Cement | Oatey
Oatey® PVC Flexible Medium Bodied Fast Set Clear Cement is recommended for spa and swimming pool applications because it is formulated to withstand pressures and vibrations associated with these installations. It also applies easily with included in-lid dauber. This clear, low VOC, medium...
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I used that on my last replumb and liked it. Thick and gives you a few seconds before sticking.It may depend on the exact chemical formula of the pvc. I have come to suspect that they are not all created equal.
I still remember the conversation some 25 years ago. There was no internet as we know it today and little industry training. I had been an electrician before so had no experience with flex but plenty with pvc and had several spa plumbing repairs blow apart at my first job in the business. So I called the flex manufacturer. Had to leave a message and wait a few days for the guy to call, but he did. I explained my situation, he said "Are you using primer on the flex?", I said "Of course.", he said "Well DON'T!", and hung up the phone.
Ahh, the good old days...
So I have not used primer on flex since. And I swear by Christys.
Red Hot Blue Glue - Low VOC - Christy's
Contractor preferred, premium formulation Medium body, very fast set All classes and Schedules thru 6″ diameter interference fit (Schedule 80 through 4″) Can be used without primer if local codes permit for non-pressure systems up to 6″ and pressure systems below 4″ Blue in color
I did not use primer but did use pvc cleaner on the flex. The flex is the original plumbing in the spa. The slip coupling i am using is sch 40 and is noticeably loose when assembled. I did go ahead and glue the joint but after several minutes, could pull the coupling off with no effort. As this is all original and the spa is about 8 years old, could the only logical explanation is the flex deteriorated/shrank in size? I will post some pictures.
Is there a "wet" pvc cement?
Thanks Again.
Is there a "wet" pvc cement?
Thanks Again.
After reaching out to a parts supplier for the manufacturer, they suggested an inside slip connector. I could then use a short pieced of flex to transition back to sch 40. Any input on inside cement joints? Also, I cant seem to find out what the pump pressure is for the spa. It is a Master Spa Twilight series 7.25. There are two 6 hp motors, this side is the single speed which I believe is just for the jets.?
Thanks James, but I did try a couple different fittings, it is definitely the O.D. of the flex.