What is BS ISO 21940-11 - Procedures and tolerances for rotors about?
Rotor balancing is a procedure by which the mass distribution of a rotor is checked and, as necessary, adjusted to ensure the unbalance tolerance is met. BS ISO 21940-11:2016+A1:2022 establishes procedures and unbalance tolerances for balancing rotors with rigid behaviour, providing guidance on the magnitude of the permissible residual unbalance for a range of machine types.
Who is BS ISO 21940-11 - Procedures and tolerances for rotors for?
BS ISO 21940-11 applies in a wide range of rotating machine design, construction and operation industries and is written for engineers and balance machine operators in balancing test facilities.
What does BS ISO 21940-11 - Procedures and tolerances for rotors cover?
It establishes procedures and unbalance tolerances for balancing rotors with rigid behaviour. It specifies:
- The magnitude of the permissible residual unbalance
- The necessary number of correction planes
- The allocation of the permissible residual unbalance to the tolerance planes
- How to account for errors in the balancing process
NOTE: In BS ISO 21940‑14, the assessment of balancing errors is considered in detail. Fundamentals of rotor balancing are contained in BS ISO 21940‑1, which introduces balancing.
BS ISO 21940-11:2016+A1:2022 does not cover the balancing of rotors with flexible behaviour. Procedures and tolerances for rotors with flexible behaviour are dealt with in BS ISO 21940‑12.
Why should you use BS ISO 21940-11 - Procedures and tolerances for rotors?
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It provides a practical balancing approach that can minimize the costs and time of the balancing process
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The standard is well established, recognized and accepted by the industry
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It can help users access new markets
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It can help users develop their expertise and improve their efficiency
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It can help users increase confidence in products and manage risk
BS ISO 21940-11 contributes to UN Sustainable Development Goal 9 on industry, innovation and infrastructure.
What’s new about BS ISO 21940-11:2016+A1:2022?
This is an amendment to BS ISO 21940-11:2016. The major change in BS ISO 21940-11:2016+A1:2022 is the addition of a new annex that has a table of suggested information that could be added to a rotor’s design drawing. This gives the necessary details for balancing of rotors with rigid behaviour, which are frequently not supplied, leading to ambiguity or even incorrect balancing tolerances.