ISO 13373-4:2021

Overview

ISO 13373-4:2021 - Condition monitoring and diagnostics of machines - Vibration condition monitoring - Part 4: Diagnostic techniques for gas and steam turbines with fluid‑film bearings - provides practical, step‑by‑step vibration diagnostic guidelines for gas and steam turbines supported on fluid‑film bearings. It codifies established good practice for field diagnostics, using flowcharts, process tables, fault tables and symptom tables to guide practitioners from anomaly detection to probable root causes.

Key topics and technical requirements

• Scope and purpose: Guidelines for vibration diagnostics specific to gas and steam turbines with fluid‑film bearings; intended as a practical aid rather than prescriptive corrective actions.
• Measurement guidance: Use of appropriate transducers - non‑contact probes (inductive, capacitive, eddy‑current) for shaft measurements and seismic transducers (accelerometers, velocity transducers) on housings - and awareness of grounding/electrical interference.
• Operational parameters: Importance of recording rotational speed, load, mounting configuration, temperature and steady/transient operating states to interpret vibration signatures correctly.
• Initial analysis: Steps to identify safety concerns (high vibration, history, operating effects) and measurement setup considerations (transducer mounting, nearby machines, foundation effects).
• Systematic diagnostic tools: Use of fault tables (Table A.1), symptom tables (Table A.2), and a structured methodology (Annex B) to correlate vibration features with likely faults.
• Decision context: Emphasis that recommended actions depend on confidence in diagnosis, prior history, severity, safety and commercial factors; the standard does not mandate specific repairs.

Practical applications

• On‑site vibration diagnostic programs for power plants, industrial turbines and rotating machinery fleets.
• Root‑cause analysis of elevated or erratic vibration in gas and steam turbines with fluid‑film bearings.
• Training and reference material for condition monitoring teams implementing vibration‑based inspection workflows.
• Input to maintenance planning, risk assessment and prioritization of remedial actions based on symptom tables and diagnostic flowcharts.

Who should use ISO 13373-4:2021

• Condition monitoring practitioners, vibration analysts and diagnostics engineers
• Maintenance technicians and reliability engineers working with turbines
• Asset owners and offshore/onshore plant operators developing vibration monitoring procedures
• Technical trainers and consultants delivering turbine vibration diagnostics

Related standards and references

• ISO 13373 series: Part 1, Part 2, Part 3
• ISO 2041, ISO 13372, ISO 21940-2
• ISO 20816 / ISO 7919 (vibration severity assessment)
• ISO/TR 19201, ISO 17359
• VDI 3839-4 (typical vibration patterns for turbines)

Using ISO 13373-4:2021 helps standardize vibration diagnostics for fluid‑film‑bearing turbines, improving consistency in fault identification and supporting safer, more reliable maintenance decisions.