Type 523 Metering Ball Valve is equipped with union ends and has an integrated scale to indicate degrees of opening (0-180°) which can be related to a flow rate at a known pressure. The direction of flow is indicated. Available in PVC and CPVC in sizes 3/8" or 1/2". Also available in metric socket fusion PP and PVDF. Solvent cemented or threaded end connections or metric fusion with true union design. Tapered groove for accurate metering and near linear flow curve - Cv of 0.8 on 3/8" (16mm) and 1.4 on 1/2" ( 20mm) sizes. Corrosion-resistant, maintenance free with long working life.