I pictured the capillaries in helium fridges as just thin medal pipes with kinks (sharp bending), which is why I thought Bernoulli's equation is what i needed to focus on. I will have to think more..
For some reason, I had trouble logging into my old account so I created a new one. Sorry for my late response.
Your response helped me understand the role of capillaries better but I'm still confused about one aspect.
Doesn't the Bernoulli's equation tell you if you have a capillary connecting...