Identify a fitting

[Marke525]

I am trying to identify a fitting. It is on a filter housing and looks like a hygienic (tri-clamp) fitting, but the dimensions don't match anything. Any suggestions?

 

[fegenbush]

What is the service of the vessel and materials of construction? That might narrow the field somewhat.

 

[Marke525]

It is a filter housing made of 316L used in a fermentation process

 

[Marke525]

I've checked:

Hygienic (tri-clover)
DIN
SMS
DS

None of these match