Sight glass assemblies, pipe assemblies including the same, and methods for assembling pipe assemblies are disclosed. Sight glass assemblies may include an annular body of a transparent material. The annular body may include a peripheral surface, an interior surface defining at least a portion of a fluid path, first and second parallel planar annular surfaces spaced a first distance apart, and at least one passage extending through the annular body from the first planar annular surface to the second planar annular surface between the peripheral and interior surfaces. In some examples, a sight glass assembly may include at least one spacing element, which may include first and second bearing surfaces. The first and second bearing surfaces may be spaced a second distance at least as large as the first distance. In some examples, the interior surface may be chemically resistant to at least one predetermined fluid.