This standard describes the minimum requirements for fiberglass-reinforced plastic weir plates, scum baffles, mounting brackets, lap plates, cover washers, and weir pans, fabricated with the matched-die molding process. Included are requirements for design, construction, dimensions, tolerances, physical properties, work quality, appearance, and installation. This standard contains the requirements for using general-purpose and chemical-resistant resins. These fabrications are used in municipal water supply service and industrial water supply service applications. Major revisions made to the standard in this edition include the following: ASTM G23 has been replaced with ASTM G152-06 and ASTM G153- 04(2010); and ASTM G26 has been replaced with ASTM G155-05a.