2.5″ FNPT Tank Port 500228 Part No. 500228 For use when adding 2.5″ FNPT ports into a water tank with a 500226 diffuser. Requires 500223 gasket. Description 2.5" FNPT Tank Port for use with 500226 Diffuser Download Part Drawing Material Stainless Steel Weight (approx.) 1.5 lbs. In stock