Unite command not working on volume

I am trying to create a simulation of a vortex flow diode but cannot unite the 3 cylinders that make up a single flow volume. Whenever I use the fix command, the volume somehow disappears from the properties window when I right click on the screen. I assume I am missing something simple in my volume setup. Is there a way to attach my file here so you all can see it?
Thanks

Avoid coincident edges and faces for robust Booleans

If the Volumes->Unite command failed with a warning (File->Log) then it is unlikely that Others->Fix will help.

If you have a volume then you need to apply the Fix tool to your volume and not the faces. If you have just faces then after using the Fix tool you will need to use the Volumes->Stitch to stitch a volume.

For robust Booleans operations you need to ensure there are no coincident edges or faces between your operands.

If this is no help then use a file sharing service, such as Dropbox, to share your simulation (prior to the unite operation) and use the Contact form to provide a link to your simulation so I can take a look.

Thanks for the response. I

Thanks for the response. I figured out that the volume would unite as long as the cylinder had a radius smaller than the cylinder it was being tangentially attached to. I would prefer that they have the same radius, but separating the radius by a millimeter is no big deal. Thanks