ANSI/ISA-75.25.01:2024

ANSI/ISA-75.25.01-2024, Test Procedure for Control Valve Response Measurement from Step Inputs, defines procedures for testing, measuring and reporting the response of control valves to step input changes. It covers throttling control valves in various environments, such as bench, laboratory and in-process and includes detailed test methods, including baseline tests, small step tests and response time tests to evaluate parameters like dead band, resolution, response time (T86), overshoot, gain ratio and sliding friction. This standard emphasizes proper instrumentation requirements, data sampling and presentation of results, aiming to provide consistent and repeatable valve response measurements without specifying acceptable performance criteria. It also includes definitions of key terms, guidance on measurement techniques and annexed procedures for sliding friction measurement, supporting improved understanding and uniformity in valve dynamic testing across industries worldwide.