Dear Tech Abby,What does 46 psi pipe stiffness really mean?  Do all pipes meet or need 46 psi?  Can you help?-          John Q. CivilJ.Q., you are not alone. 

Dear Tech Abby:  Do I have to use a crushed stone backfill for my PVC sewer pipe installation?  --That 70’s EngineerDear That 70’s Engineer:  Good question… the

Every sewer has them… every few hundred feet… you can’t avoid it if you are in the sewer industry... Got a guess?... That’s it… MANHOLES. Ahh yes, the beautiful