Patent ID: 7654219

Claim:
A sight glass assembly, comprising: an annular body of a transparent material, the annular body comprising: a peripheral surface, an interior surface defining at least a portion of a fluid path, a first planar annular surface, a second planar annular surface parallel to and spaced a first distance from the first planar annular surface, and at least three passages extending through the annular body from the first planar annular surface to the second planar annular surface, wherein at least a part of each of the passages is disposed between the peripheral surface and the interior surface; and at least three spacing elements disposed in at least three of the passages, wherein each of the spacing elements extends along one of the passages from a first bearing surface to a second bearing surface, the first bearing surface is spaced a second distance from the second bearing surface, the second distance is at least as large as the first distance, and the spacing elements comprise a material having a compressive stiffness greater than the compressive stiffness of the transparent material.