Are there any rules of thumb for the design length of transition tubes in order to prevent condensation at the room temperature end?

By “transition tube,” I mean some standard size (O.D. and wall thickness) type 304 stainless steel tube with either 4 K or 80 K at one end and room temperature (300 K) convection at the other end.

Basically, what I’m asking is this: Is there some standard relation people use for length depending on the cross-sectional area – one relation for the 4 K case and another for the 80 K case – in order to prevent condensation, and possibly subsequent ice ball formation?