What is the allowable ring deflection for PVC pipes

[yahoo123]

I read that it is 5% for AWWA and 7.5% for ASTM. However I looked through the M23 and it does not give the allowable ring deflection and I also can't find the ASTM document that publish a 7.5% limit.

Can someone tell me where I can cite these limits?

 

[LCruiser]

Theoretically, it depends on wall thickness and pipe diameter - aka strain. Thinner walls permit larger deflection.

 

[stanier]

Standards normally dictate allowable ring deflection. AS 2566.1 allows 7.5% for PVC-U & PVC-O. But deflection is but one criteria.

 

[rconner]

While virtually all modern flexible pipe materials can be deformed in a laboratory far beyond cited limits without immediately breaking the walls, this does not mean as others have at least inferred that very substantial allowable ring deflection in the field is necessarily a good idea (for arguably multiple reasons). See my recent response and references with regard to your pipe stiffness inquiry on this same page, as well as perhaps spirited past discussions associated with buried pipe ring deflection that include as you will find some opposing viewpoints such as

http://eng-tips.com/viewthread.cfm?qid=142221,

and I suspect others you could find with the Advanced Search feature.]