ISO 20816-4:2018
Mechanical vibration — Measurement and evaluation of machine vibration — Part 4: Gas turbines in excess of 3 MW, with fluid-film bearings
Mechanical vibration — Measurement and evaluation of machine vibration — Part 4: Gas turbines in excess of 3 MW, with fluid-film bearings
- Статус документа:
- Действующий
- Формат:
- Электронный (PDF)
- Количество страниц:
- 21
- Дата публикации:
- 18 июня 2018 г.
- Издание:
- ISO IS 20816 edition 1 version 1
- ICS:
- 17.160
This document is applicable to land-based gas turbines with fluid-film bearings and power outputs greater than 3 MW and an operating speed under load between 3 000 r/min and 30 000 r/min. In some cases (see the list of exclusions below), this includes other rotating machinery coupled either directly or through a gearbox. The evaluation criteria provided in this document are applicable to the vibration of the main input and output bearings of the gearbox but are not applicable to the vibration of the internal gearbox bearings nor to the assessment of the condition of those gears. Specialist techniques required for evaluating the condition of gears are outside the scope of this document. This document is not applicable to the following: i) gas turbines with power outputs greater than 40 MW at rated speeds of 1 500 r/min, 1 800 r/min, 3 000 r/min or 3 600 r/min (see ISO 20816-2); ii) aero-derivative gas turbines (including gas turbines with dynamic properties similar to those of aero-derivatives); NOTE ISO 3977-3 defines aero-derivatives as aircraft propulsion gas generators adapted to drive mechanical, electrical or marine propulsion equipment. Large differences exist between heavy-duty and aero-derivative gas turbines, for example, in casing flexibility, bearing design, rotor-to-stator mass ratio and mounting structure. Different criteria, therefore, apply for these two turbine types. iii) gas turbines with outputs less than or equal to 3 MW (see ISO 7919-3 and ISO 10816-3); iv) turbine driven generators (see ISO 20816-2, ISO 7919-3 and ISO 10816-3); v) turbine driven pumps (see ISO 10816-7); vi) turbine driven rotary compressors (see ISO 7919-3 and ISO 10816-3); vii) the evaluation of gearbox vibration (see this clause) but does not preclude monitoring of gearbox vibration; viii) the evaluation of combustion vibration but does not preclude monitoring of combustion vibration; ix) rolling element bearing vibration. This document establishes provisions for evaluating the severity of the following in-situ broad-band vibrations: a) structural vibration at all main bearing housings or pedestals measured radial (i.e. transverse) to the shaft axis; b) structural vibration at thrust bearing housings measured in the axial direction; c) vibration of rotating shafts radial (i.e. transverse) to the shaft axis at, or close to, the main bearings. These are in terms of the following: - vibration under normal steady-state operating conditions; - vibration during other (non-steady-state) conditions when transient changes are taking place, including run up or run down, initial loading and load changes; - changes in vibration which can occur during normal steady-state operation.
Abstract
Overview
ISO 20816-4:2018 - Mechanical vibration - Measurement and evaluation of machine vibration - Part 4 provides guidance for measuring and evaluating vibration of land‑based gas turbines with fluid‑film bearings, rated above 3 MW and running under load between 3 000 r/min and 30 000 r/min. The standard defines measurement locations, instrumentation considerations and broad‑band evaluation criteria for main bearing housings/pedestals, thrust bearings and rotating shafts. It also clarifies exclusions (for example, aero‑derivative turbines, small turbines ≤3 MW, certain large turbines covered by ISO 20816‑2) and limits application to gearbox input/output bearings (not internal gearbox bearings or gear condition assessment).
Key topics and requirements
- Scope and exclusions: Applies to land‑based gas turbines >3 MW (3 000–30 000 r/min); excludes aero‑derivatives, turbine‑driven generators/pumps/compressors and rolling‑element bearing vibration.
- Measurement procedures: Conforms to ISO 20816‑1 general requirements. Specifies measurements on non‑rotating parts and rotating shafts, with sensor placement guidance (typically two orthogonal radial transducers per main bearing cap/pedestal; axial measurements for thrust bearings).
- Instrumentation and frequency range: Monitoring systems shall cover broad‑band vibration from 10 Hz up to at least three times the maximum normal operating frequency or 500 Hz, whichever is greater. Notes on low‑frequency linearization when using velocity transducers.
- Evaluation criteria: Two principal steady‑state criteria are provided:
- Criterion I - vibration magnitude (assessment of absolute vibration levels);
- Criterion II - change in vibration magnitude (assessment of trends or sudden changes). Transient (run‑up, run‑down, loading) and non‑steady conditions are also addressed. Annexes include evaluation zone boundaries and guidance on alarm/trip setting.
- Environmental and measurement integrity: Highlights influences such as temperature, electromagnetic fields, structure‑borne noise, cable effects and transducer mounting.
Applications and users
ISO 20816‑4 is used for:
- Commissioning and acceptance testing of heavy‑duty land gas turbines
- Routine vibration monitoring and periodic vibration surveys
- Setting alarm/trip thresholds for plant protection (see Annex C)
- Condition monitoring and maintenance planning (broad‑band evaluation) Primary users: vibration engineers, rotating‑equipment condition monitoring teams, maintenance engineers, OEMs and plant asset managers.
Related standards
- ISO 20816‑1 (general guidelines)
- ISO 20816‑2 (large gas turbines)
- ISO 7919‑3, ISO 10816‑3 / ISO 10816‑7 (other machine classes)
- ISO 13373 (vibration condition monitoring)
- ISO 2954, ISO 5348 (transducer and mounting guidance)
Keywords: ISO 20816-4:2018, mechanical vibration, gas turbines, fluid‑film bearings, vibration measurement, vibration evaluation, bearing housings, rotating shafts, condition monitoring.
Технические детали
- Технический комитет
- ISO/TC 108/SC 2 - Measurement and evaluation of mechanical vibration and shock as applied to machines, vehicles and structures
- SKU
- ISO 20816-4:2018
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