UNI flanges face finish

[ElCidCampeador]

Hi,

what is the purpose of the 3 big concentric grooves on face of UNI flanges? What are the differences with phonographic one?

Thank you

 

[r6155]

Spiral (phonographic)groove serrations are not used with low viscosity (low density) fluids because the probability of leakage is high. Failure will allow a fluid to leak through the spiral channel until reaching the outside diameter of the gasket.

Regards