ANSI/ISA-75.11.01-2013

ANSI/ISA-75.11.01-2013, Inherent Flow Characteristic and Rangeability of Control Valves, defines the inherent flow characteristics and rangeability of control valves. It establishes standardized terminology, flow characteristic definitions and acceptable deviations between actual valve performance and manufacturer-stated values. This standard specifies how manufacturers should present flow coefficients (Cv) at various valve travel positions. It sets criteria for allowable deviations in flow coefficient and slope during testing to promote consistency and reliability. It also outlines the method for calculating inherent rangeability based on these deviations. Additional guidance is provided on the use of metric units, patent considerations and safety requirements.