Initial Ring Deflection

All pipes must meet the initial ring deflection levels of no visual evidence of cracking or crazing (Level A) and no structural damage to the pipe wall (Level B) when vertically deflected between two parallel flat plates or rods.

 

Deflection

level

Stiffness class

SN2500

SN5000

SN10000

A

15%

12%

9%

B

25%

20%

15%