My sand filter recently started to split at the seam. Pool company here said my pump was too powerful for the filter. Pump is 133gpm and he said the filter was good for up to 75gpm, but it worked for almost 2 years. Regardless, I purchased a new cartridge filter rated for 150gpm. Skimmer is 1.5" PVC to pump. Pump is 2" PVC to filter. Filter out is 2" initially with a 90° out to 2" and then reduced to 1.5" to pool return jet. Pool is 24' round above ground. All PVC joints were sanded, purple primed and blue glued. Four times now I have turned on the pump and get less than 5 minutes until one of the PVC connections between the filter and pool (2" to 1.5" reduction) come apart. Only difference from the previous setup that worked for two years is the pump to filter PVC run used to be 1.5" and is now all 2". All suggestions? My pool guy actually told me it was too hot for him to come out and do this.
PVC connections not holding
- Thread starter Dbarry456
- Start date
Have you tried turning the pump speed down (or is it a single speed)? That’s really weird. I’m not sure how much water pool pumps normally can push but that does seem like a big pump. But PVC should be able to hold quite a bit of pressure. I assume you’re letting it dry and twisting it a bit when it’s being glued?
Thanks for the reply. Pump is 1.5hp single speed. I've had it for 18-20 months. I got it for more vacuum power and it is night and day better than the two previous more expensive pumps. I read where the pump gpm flow has to match the filter flow rate so I got this 150gpm rated cartridge filter. Each time it has come apart I wait a day before sanding, priming and gluing the PVC. I'm going to give it one more try tomorrow before I punt on glued PVC and try changing to threaded connections. I'm a tech guy and this is out of my wheelhouse.
That combination of very large pump and sand filter was a disaster waiting to happen.
A). Speaking as an old pool guy, you need new pool guy if he won'tat least try to do the repair. B). You can't keep reusing a fitting that has come apart, they don't properly weld together the second time. You can get away with it on the suction side but you see the problem on the pressure side. C). A pump that can move that much water is trying to shove it through pipe that should have no more than 48 (1.5") to 88 (2") gpm in flow. Time to at least downsize that pump or get a VSP after repairs are made.
If the fittings are coming apart, you are doing something wrong.
The pump cannot produce enough pressure to separate properly glued schedule 40 PVC fittings.
Maybe you have the wrong glue or bad glue or the wrong pipe or the wrong fittings or maybe the procedure for gluing is incorrect.
Can you show pictures of everything?
The pump cannot produce enough pressure to separate properly glued schedule 40 PVC fittings.
Maybe you have the wrong glue or bad glue or the wrong pipe or the wrong fittings or maybe the procedure for gluing is incorrect.
Can you show pictures of everything?
The pump cannot do more than 40 psi and the joint should be able to do 180 psi.
So, you are definitely doing something wrong.
So, you are definitely doing something wrong.
I didn’t realize that reusing fittings was possibly at play here. Almost guaranteed that’s a problem. I did find it odd about sanding the fittings as I’ve never had to sand fittings.
It is surprising you say you are able to reuse the previously used fittings - even with sanding: If the joint has been allowed to cure overnight, you should not be able to pull apart a fused joint. The primer and adhesive melt into the fittings' plastic and they weld together and the volatile component of the adhesive evaporates leaving a hardened joint /bond line, this is different than merely using glue that is sticking two items together.
If you have moisture in a joint when it’s glued and put pressure on it too soon, I’ve had one burst on me like that. But the fix is to cut out that bad joint and glue in a brand new one. Reusing PVC joints doesn’t work and in the cases where it doesn’t come undone is more likely due to luck.
Are you sure the pool guy is using schedule 40 pvc for pressure fittings, and not just schedule 40 DWV pipe.
All schedule 40. I did one more disassembly, sanding the joints that came undone, primed those joints and really gobbed the PVC glue on. I did the twist of pipe and held for several minutes. Waited until the next morning. All has worked running 24x7 the past week.