Overview
ISO 18129:2015 - Condition monitoring and diagnostics of machines - Approaches for performance diagnosis - provides guidance on applying performance monitoring and diagnostics across single machines, groups of machines, or complete industrial installations throughout their lifetime. The standard explains how to compare measured descriptors (actual signals such as power, flow, speed) with expected descriptors derived from models to detect inefficiency, deterioration, faulty instrumentation and to quantify performance losses. It emphasizes practical implementation for thermodynamic and energy-conversion processes and supports energy-efficiency and emission-reduction goals.
Key topics and technical requirements
- Types of monitoring: Online performance monitoring, offline performance analysis, and online monitoring with validation.
- Modelling and descriptors: Use of process models (e.g., thermodynamic cycle models) to generate expected descriptors for comparison with measured descriptors.
- Operating condition handling: Two reference approaches - monitor at actual measurement conditions or convert measurements to defined reference conditions for trending.
- Installation guidance: Preconditions, planning, operation analysis, definition of operation states (steady state, nominal, partial load), model adjustment and testing of monitoring systems.
- Methods & requirements: Methodology, plausibility checks, cycle times and averaging, implemented calculations and input parameters, and validation procedures.
- Data validation & reconciliation: Recommendation to use data validation/reconciliation (e.g., VDI 2048-1) to improve measurement consistency and enable closed energy/mass balances.
- Interpretation & reporting: Guidance on data interpretation, assessment criteria, reporting requirements and accuracy testing for benchmarking.
- Informative annexes: Examples and recommended inputs/descriptors (pump performance, gas-turbine hydraulic clearance optimization).
Applications and who uses it
ISO 18129:2015 is intended for:
- Plant operators and control-room staff aiming to optimize operation and reduce energy costs.
- Maintenance and reliability engineers for early detection and quantification of deterioration (erosion, fouling, corrosion).
- Energy managers and sustainability teams focused on efficiency and emission reduction.
- Instrumentation and condition-monitoring specialists implementing monitoring systems and data validation.
- Consultants and OEMs designing diagnostic models and performance-monitoring solutions.
Practical uses include performance trending, fault localization, benchmarking equipment efficiency, validating measurement suites, and supporting corrective actions to restore optimal operation.
Related standards
- ISO 13372 - Condition monitoring and diagnostics of machines - Vocabulary
- ISO 13379-1 - Data interpretation and diagnostics techniques - General guidelines
- ISO 17359 - General guidelines for condition monitoring and diagnostics
- VDI 2048-1 - Data validation/reconciliation guidance (recommended in the standard)
Keywords: ISO 18129:2015, performance monitoring, diagnostics of machines, condition monitoring, performance diagnosis, measured descriptor, expected descriptor, data reconciliation, industrial installation, energy efficiency.