An expanding ferrule is normally slipped over the tube and rough welded into place.  It is usually used a socket to fit over the tubing.  

The groove ID could grasp the outside of the tube and it is generally used to repair the process lines.

l  Manufacturing and design according to 3A Sanitary Standard and the specification for USA tube sizes.

l  Size range:  1" ~ 4"

l  oughness:  Ra 0.8μm (Ra 32μinch)

l  Stainless steel material:  304ss, 316L 

l  Gasket : EPDM , Silicone , FKM , PTFE
l  Manufacturing and design according to 3A Sanitary Standard.