Specialized pieces, table of thickness and connections.
Drawing labels, details, and other text information extracted from the CAD file (Translated from Spanish):
mm., elbow, tee, yee, elbow, in., elbow, normal, diameter, mm., in., tee, side, in., mm., cross, mm., in., mm., in., yee, elbow long radio, side, reduction, in., in., mm., in., mm., in., elbows, mm., in., mm., cross, mm., in., reduc., in., mm., mm., elbow, tee, yee, elbow, in., elbow, normal, diameter, mm., in., tee, side, in., mm., cross, mm., in., mm., in., yee, elbow long radio, side, reduction, in., in., mm., in., mm., in., elbows, mm., in., mm., cross, mm., in., reduc., in., mm.