You probably need a non linear simulation for this to get good accuracy. If you are attempting the whole mechanism you would definitely need an NL solution. That said though it should be reasonably attainable but it may have some challenges. Just doing the tube itself should be pretty straight forward. I don't download things so better to post images of what you have and i would be happy to comment.
I have two concerns based on your setup:
1) I noticed your model has a circular cross-section
From the limited searching I did it seems Bourdon tubes rely on a non-circular cross section for their effect. Wikipedia states "The Bourdon pressure gauge uses the principle that a flattened tube tends to straighten or regain its circular form in cross-section when pressurized...."
So it would seem a non-circular (oval or "flattened") cross section is crucial to capturing the behavior. Forgive me if I'm off base here
2) This is a geometrically nonlinear problem
I noticed you have the study set up to run in Large Displacement mode, which is the best option available in a Static analysis.
Do you have access to Nonlinear analysis study type? There's an option that can be enabled in the Solver properties to "Update load direction with deformation". Without this option enabled, the force/pressure directions do not change as the part deforms. This is pretty much required for pressurization problems with large scale deformation (such as inflating a balloon or membrane) Since the deformations are probably more subtle here I am not sure if it will be required, but it is a good thing to know about
I would try to verify if the cross-section of the tube is correct, and then also look into see if you have access to the Nonlinear study type (requires Simulation Premium)
Ryan, you are correct, the tube will be a flattened circle (they begin as a tube then get rolled and they flatten). I have it designed as an ellipse with the current model having height and width equal. I guess this leads to another question, do I have this designed right if I elongate the width or do I need to make it more of a slot shape? We know what the OD will be of the circle before being flattened but we are getting tripped up on how to make the formula correct to appropriately size the "crushed" tube. Looks like I do not have non linear simulation, so I will talk with my local distributor and see what will go into purchasing this as I foresee running similar simulations often as we begin to go into our own Bourdon tube designs. Thank you for responses Ryan and Bill. I apologize for my "green-ness" in the world of simulation.