Overview
ISO 10816-6:1995, "Mechanical vibration - Evaluation of machine vibration by measurements on non-rotating parts - Part 6: Reciprocating machines with power ratings above 100 kW", defines procedures for measuring and evaluating vibration on the non-rotating parts of large reciprocating machines. It applies to machines mounted rigidly or resiliently with power ratings above 100 kW (examples: marine propulsion engines, diesel generator set engines, gas compressors, diesel locomotive engines) and excludes road vehicles. The standard focuses on overall vibration measured on the machine structure to classify vibration severity and to protect attached equipment and surroundings.
Key topics and requirements
- Measurement scope: Overall r.m.s. values of displacement, velocity and acceleration derived from broad-band signals (recommended frequency range 2 Hz to 1 000 Hz; typical excitation 2–300 Hz).
- Measurement points & directions: Preferred measurement positions on the main structure and three machine-related main directions to ensure consistent comparisons between machines.
- Instrumentation & accuracy: Instruments must deliver overall r.m.s. displacement, velocity and acceleration with accuracy typically ±10% (10–1 000 Hz) and ±15% (2–10 Hz). Accelerometer outputs may be integrated to derive velocity/displacement - care is required to avoid processing errors.
- Operating conditions: Measurements must be taken at steady-state operating conditions; the vibration severity is based on the maximum vibration across the approved power and speed range.
- Severity grading & classification: Vibration severity grades (numeric) are assigned from measured displacement, velocity and acceleration. The machine’s severity grade is the highest grade among these measurements. Annex A provides classification numbers and guide values for different reciprocating machine types.
- Scope limitations: Shaft and torsional vibration, and noise, are outside the part’s scope. Measurement guidance applies to machine frames and mounted ancillaries; internal component issues may need special or local measurements.
Practical applications and users
- Applications
- Acceptance testing and factory/site commissioning of reciprocating engines and compressors
- Operational condition monitoring and trend analysis
- Assessing suitability of machine foundations and isolation
- Evaluating effects on machine-mounted auxiliaries (turbochargers, pumps, piping)
- Supporting maintenance decisions and troubleshooting vibration-related failures
- Who uses ISO 10816-6
- Vibration analysts and test engineers
- OEMs and engine manufacturers
- Marine engineers and shipyards
- Power plant and diesel generator operators
- Locomotive and large-compressor maintenance teams
- Procurement and quality assurance professionals
Related standards
Keywords: ISO 10816-6, mechanical vibration, reciprocating machines, vibration severity, non-rotating parts, vibration measurement, accelerometer, r.m.s. vibration, marine engines, diesel generators.