PVC fitting crack

[__Will___]

Hello everyone; love the forum. I replaced a faulty well pressure tank with a cycle stop valve when we moved in 2020. 1-1/4" PVC plumbing comes into the closet then transitions to a 1" male threaded PVC fitting at the metal female cycle stop valve. Twice a crack just past the threads has developed in this PVC fitting (area of crack circled in red below). Any ideas why this would be occurring?

 

[Valveman]

That is an unusual place for a crack. Since you have had two of them fail I would say you got a batch of bad fittings. You might try changing from 1 1/4" to 1" before the elbow. Use a 1" elbow and maybe a piece of sch 80 in 1" that is threaded on one end.

 

[Sponsor]

 

[wwhitney]

Query based on theory, not experience: are the male threads metal, and if so, is this an example of downside of metal male threads into plastic female threads? I.e. cracking is a sign of overtightening, which is only a problem for that combination?

Cheers, Wayne

 

[__Will___]

Male threads are plastic, female threads are metal. I tightened only with my hand. I've noticed a slight movement in the pipes when the irrigation valves open and cause a quick drop in pressure. Should I attempt to affix the PVC pipes to the floor or wall? The run to the CSV fitting is only about 18 inches.

 

[Valveman]

Is it cracked in the threads?

 

[__Will___]

No, the crack is just past the threads at the very end of the wall of the slip joint.

 

[John Gayewski]

Take a picture from farther away. Hard to see what's actually happening here. I suspect gravity is the cause.

 

[Greenmonster123]

PVC male adapters are very weak fittings, I avoid them whenever I can. I use such 80 toe nipples in their place.

 

[Reach4]

A schedule 80 coupling would be stronger if you want to go that way. You can glue schedule 40 and schedule 80 together.

836-010 - Spears 836-010 - 1" PVC Schedule 80 Male Adapter (MIPT x S)

Spears 836-010 - 1" PVC Schedule 80 Male Adapter (MIPT x S) - 836-010: <br><ul> <li>1" x 1" <li>MIPT x Socket</ul>

www.supplyhouse.com

 

[__Will___]

Thanks for the responses, everyone.