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Free Engineering Tool #023

Vibration Limits — Hydro Turbines & Pump Units

Evaluate vibration severity for hydraulic turbines, pump-turbines, and pumps per ISO 20816-5. Supports bearing housing velocity and shaft displacement measurements.

ISO 20816-5 Zones A/B/C/D Hydro Machines
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Results

A
B
C
D
Vibration Zone
Measured Value
Recommendation
ZoneBoundaryDescription

ISO 20816-5 Scope

ISO 20816-5 specifies vibration evaluation criteria for hydraulic machines including Kaplan, Francis, and Pelton turbines, pump-turbines, and pumps used in hydroelectric power plants. It covers both vertical and horizontal machine configurations.

Bearing Housing Vibration — Vertical Machines

Broadband vibration velocity measured on the bearing housing in mm/s RMS, typically 10–1000 Hz range. Applies to vertical Kaplan, Francis, pump-turbine, and pump units. The zone boundary values on this page are simplified guideline values from the ISO 10816/20816 series; the machine-group- and speed-specific tables of ISO 20816-5 differ in detail and should be consulted for contractual or acceptance evaluations.

Zone BoundaryVelocity (mm/s RMS)
A/B2.8
B/C5.3
C/D8.5

Bearing Housing Vibration — Horizontal Pelton

Horizontal Pelton turbines have lower allowable limits due to the bearing arrangement and impulse loading characteristics.

Zone BoundaryVelocity (mm/s RMS)
A/B2.3
B/C4.5
C/D7.1

Shaft Displacement — Vertical Machines

Shaft relative displacement is measured with proximity probes, expressed as peak-to-peak displacement in μm.

Zone BoundaryDisplacement (μm p-p)
A/B80
B/C160
C/D260

ℹ️ Note: Vertical hydro machines have unique vibration characteristics due to gravity acting along the shaft axis. Thrust bearing condition and hydraulic forces (draft tube surge, cavitation) significantly affect vibration behavior.

⚠️ Important: Both bearing housing and shaft vibration should be monitored. The worse of the two assessments governs the overall evaluation. Operating conditions (load, head, tailwater level) strongly influence vibration levels in hydro machines.

Vibromera — Portable Balancing & Vibration Analysis
Professional vibration analyzers and field balancing systems for hydroelectric machinery. ISO 20816 compliant evaluation on-site. Used in 50+ countries.
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Nikolai Shelkovenko

Nikolai Shelkovenko

Nikolai Shelkovenko is a vibration analysis engineer and the founder and CEO of Vibromera. For more than 15 years he has balanced rotating equipment in the field rather than on a test bench: mulchers, industrial fans, crushers, centrifuges, shafts and spindles. That work is what the Balanset instruments grew out of — they were designed as a tool a specialist can carry to the machine and use alone, on site, not as laboratory equipment. Vibromera was founded in 2017 and has been based in Porto, Portugal, since 2023. Development, assembly and support of the Balanset line all happen here. The flagship instrument is the Balanset-1A, a portable analyser for single- and two-plane balancing and for vibration diagnostics. Nikolai is personally involved in customer support, in working through difficult balancing cases and in the development of the software. He works with customers worldwide, in any language.

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