When we are using a v-band turbine housing, both the housing input and ouput will need a flange to connect.

Here in this video it shows you how a ring casting is machined into a install flange for v-band stainless steel turbine housing.

Machining stainless steel v-band turbine housing

Face milling stainless steel turbo turbine housing inlet flange

Machining IS38 turbine housing's bearing housing connection

Turbine housing G30 G35 AR1.21 V-band inlet outlet

Turbo G30-660 with turbine housing AR1.21 v-band inlet outlet