Sight glass

A sight glass assembly configured to permit viewing into an interior of a pipe fitting, the sight glass assembly comprising:

• a tubular housing defining an inner housing surface, an outer housing surface, a first housing end, and an opposed second housing end, the inner housing surface defining a housing bore extending through the housing from the first housing end to the second housing end;
• a tubular adapter defining an inner adapter surface, an outer adapter surface, a first adapter end coupled to the housing, and an opposed second adapter end configured to be coupled to the pipe fitting, the inner adapter surface defining an adapter bore extending through the adapter from the first adapter end to the second adapter end;
• a transparent viewport positioned in the housing bore such that the interior of the pipe fitting is viewable through the housing bore, the viewport, and the adapter bore;
• an annular retaining ring positioned between the viewport and the adapter and configured to securedly couple the viewport to the housing, the annular retaining ring defining an inner ring surface, an outer ring surface, a first ring end, and an opposed second ring end, the outer ring surface being threaded from the first ring end to the second ring end and configured to matingly engage threads defined in the inner housing surface of the housing;
• and
• a stiffener positioned between the first housing end and the viewport, the stiffener configured to prevent flexing of the viewport due to fluid pressure exerted on the viewport from fluid in the pipe fitting, the stiffener defining an inner stiffener surface, an outer stiffener surface, a first stiffener end, and an opposed second stiffener end.

A method of viewing an interior of a pipe fitting, the method comprising:

• providing a sight glass assembly comprising:
• a housing defining an inner housing surface, an outer housing surface, a first housing end, and an opposed second housing end, the inner housing surface defining a housing bore extending through the housing from the first housing end to the second housing end;
• an adapter defining an inner adapter surface, an outer adapter surface, a first adapter end coupled to the housing, and an opposed second adapter end configured to be coupled to the pipe fitting, the inner adapter surface defining an adapter bore extending through the adapter from the first adapter end to the second adapter end;
• a transparent viewport positioned in the housing bore;
• an annular retaining ring positioned between the viewport and the adapter and configured to securedly couple the viewport to the housing, the annular retaining ring defining an inner ring surface, an outer ring surface, a first ring end, and an opposed second ring end, the outer ring surface being threaded from the first ring end to the second ring end and configured to matingly engage threads defined in the inner housing surface of the housing;
• and
• coupling the second adapter end of the adapter to the pipe fitting;
• and
• viewing the interior of the pipe fitting through the housing bore, the viewport, and the adapter bore.