ISO 8130-4:2021 “Powder coatings – Part 4: Calculation of the lower explosion limit” (GB/T 21782.4-2008) provides a calculation method of the lower explosion limit of powder coatings, that is, the minimum concentration of powder coatings in the air can form an explosive mixture.
A Preface
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ISO 8130-4-2021 – Powder coatings – Part 4: Calculation of lower explosive limits

This document has been prepared by Technical Committee ISO/TC 35 (Paints and varnishes), Subcommittee SC 9, General test methods for paints and fading, in cooperation with the European Committee for Standardization (CEN) Technical Committee CEN/TC 139, Paints and Varnishes, in accordance with the Technical Cooperation Agreement (Vienna Agreement) between ISO and CEN.

The second edition removes and replaces the technically revised first edition (ISO 8130-4:1992) and ISO 8130-4 Technical Corrigendum 1:1993.

The main changes are as follows:

– The range has been modified to distinguish between the calculation and estimation of the lower explosion limit;

– The definition of lower explosion limit (3.1) of coating powder is clarified, and short-term LEL is introduced;

— SI unit of lower explosion limit has been corrected;

— The test report (Article 8) shall indicate whether the lower explosion limit has been calculated or estimated;

– The bibliography contains two new references;

– The text has been edited and revised, and the normative references have been updated;

-Some text has been moved from scope to introduction.

A list of all parts in the ISO 8130 series can be found on the ISO website.

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ISO 8130-4-2021 – Powder coatings – Part 4: Calculation of lower explosive limits

Introduction
Reliable methods of measuring the lower explosive limit or total calorific value require the use of special equipment that may not be readily available.

ISO 6184-1 gives the method for determining the explosive index of combustible dust in air. However, this approach is very complex and requires considerable expertise.

The lower explosion limit can also be estimated by the sum of the total calorific value of the individual components in the paint powder. This is an estimate because it is not possible to know or obtain the total calorific value of the ingredients.

This calculation method can reduce the explosion limit, which is proved to be satisfactory when applied to coating application equipment.

Caution encourages comparison with direct methods (e.g. EN 14034-3[2]) to determine the lower explosion limit.

1 Scope
This document specifies the method for calculating the lower explosive limit of paint powder, that is, the minimum concentration of paint powder in air to form explosive mixtures. It is based on the measurement of the total calorific value of the product, determined by the method described in ISO 1928.

ISO 8130-4-2021 – Powder coatings – Part 4: Calculation of lower explosive limits

2 Normative references

The following documents are referenced in the text in such a way that some or all of their contents constitute the requirements of this document. For dated references, only the cited version applies. For undated references, the new version of the reference (including any revisions) applies.

ISO 1928, coal and coke — Determination of gross calorific value

ISO 8130-14, coating powders — Part 14: Vocabulary

ISO 15528, Paints, varnishes and raw materials for paints and varnishes – Sampling

3 Terms and definitions

For the purposes of this document, the terms and definitions given in ISO 8130-14 and the following shall apply.

ISO and IEC maintain terminology databases for standardization at the following addresses:

– ISO online browsing platform: available at iso.org/obp

– IEC Electronic Encyclopedia: available at electropedia.org/

3.1 Lower explosion limit
By Lyle

Powder The minimum concentration of paint powder as a mixture of powder and air below which explosion is not possible

Note 1: The lower limit of explosion is expressed as g/cubic meter (g ⋅ m-3).

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