Sand Filter Keeps Cracking

[Mikey311]

Bought house with pool in 2021 and the multi-port valve on my sand filter just cracked for the 3rd time... I replaced with new OEM part the prior two times.

I obviously don't want to replace it again just to have it Crack again.

I assume the plumbing on the left side is putting too much downward pressure on the valve?? After the last occurrence I didn't even reconnect the backwash line because it wasn't lining up well and figured I would just connect when I needed to backwash.

Should I replumb the two lines on the left with the next replacement??

Other thoughts? The image below shows where the Crack keeps occurring.

 

[proavia]

If the plumbing at the unions doesn't line up it will put excessive stress on the connected pieces - eventually causing something to fail.

 

[JoyfulNoise]

It’s not really obvious how far off of level the plumbing is … or where the crack is.

Honestly, I find it hard to believe that the MPV body would crack BEFORE one of the glue joints would go.

Are there any abnormal pressure readings? You signature says 1/2HP single speed pumps, is that right?

 

[Mikey311]

It’s not really obvious how far off of level the plumbing is … or where the crack is.

Honestly, I find it hard to believe that the MPV body would crack BEFORE one of the glue joints would go.

Are there any abnormal pressure readings? You signature says 1/2HP single speed pumps, is that right?

The Crack has occurred on the right side the last 2 times.... see new image below.

Signature should read 1.5hp single speed pump.

 

[JoyfulNoise]

Thanks for clarifying where the crack happens.

Still seems really odd that it would crack there repeatedly like that. Seems to indicate an issue other than just stressed pipes.

Have you noted anything out of the ordinary like excessively big system pressure?

Has the sand media been inspected or changed recently?

 

[Mikey311]

Sand was changed last year. I got a new valve and removed the old one and saw this.... Crack in the pipe on the lateral assembly pipe. In the same side as the crack.... this assembly and the value were replaced within the last 1-2 years.... but are fairly new. Sigh.

It is possible to just replace the pipe on that assembly or do I need another full unit?

 

[JoyfulNoise]

Wow. That split also raises my suspicions a lot. I don’t think this is a manufacturing defect problem, I think there’s something wrong with your plumbing or the way the filter is set up that’s causing excessive pressure to build up and that is what is splitting these parts.

Maybe @1poolman1 or @JamesW can help here. I’m not familiar enough with sand filters and pump/plumbing configurations to give an appropriate answer.

 

[Mikey311]

Wow. That split also raises my suspicions a lot. I don’t think this is a manufacturing defect problem, I think there’s something wrong with your plumbing or the way the filter is set up that’s causing excessive pressure to build up and that is what is splitting these parts.

Maybe @1poolman1 or @JamesW can help here. I’m not familiar enough with sand filters and pump/plumbing configurations to give an appropriate answer.

I tend to agree that the plumbing / sand filter position / location is the problem as it seems that the plumbing it putting too much pressure on the right side of the value / internal pipe hence the cracks.

I bought some new pvc to try and adjust the plumbing for a more proper fit. At this point i just need to konw if i need to buy another brand new lateral assembly or is it possible just to replace the pipe or even cut it and re-extend it back up to proper height with new pipe. I just want to fix it right one last time.

Of course any other advice is appreciated, thanks for chiming in .

 

[1poolman1]

Wow. That split also raises my suspicions a lot. I don’t think this is a manufacturing defect problem, I think there’s something wrong with your plumbing or the way the filter is set up that’s causing excessive pressure to build up and that is what is splitting these parts.

Maybe @1poolman1 or @JamesW can help here. I’m not familiar enough with sand filters and pump/plumbing configurations to give an appropriate answer.

Have seen those tanks split at seams, especially if used with a spa, but have never seen the standpipe or valve crack like that. It could just be the picture's perspective, but there seems to be a lot of misalignment in the plumbing.