Simple brackets for tubing manometer

These clips are used to fasten flexible 3/8" tubing to a panel to construct a simple differential manometer.  The tubing is partially filled with water and then one end is connected to a source of pressure that is different than the ambient.  For example, to monitor the performance of a ducted filtration system, the pressure differential between the interior and exterior of the duct indicates the filter status.  If the filter becomes clogged, then the differential pressure increases, which causes the water levels to become further apart.  

The first layer of these brackets has very small contact area on the outside edges, so brims may be needed.  However, to eliminate the brims on the inside, braces placed along the ends keep the brim completely on the outside.  The braces can simply be clipped off after the print is complete.

This item was created using Onshape.  Supposedly, this link will enable you  to view the design file:

https://cad.onshape.com/documents/303a67c1811e274b69a6cdcf/w/f517e667607602c50de02bf6/e/d737d498ab3332d0c92e8d02?renderMode=0&uiState=66435f2224a2832b7669a8df