Overview
ISO 22031:2021 defines standardized procedures for sampling and testing cleanable filter media removed from filters while the system is in operation. It covers both woven and nonwoven fabric filter media (bag filters) and specifies how to remove used filter elements from dry dust collectors, prepare and clean sampled media, cut test specimens, measure key parameters, and store/transport samples safely to protect workers and laboratory staff. The standard also includes guidance for representative sampling locations within a filter array and documentation templates (example test reports and results).
Key topics and requirements
- Representative sampling: selection of sampling blocks and number/position of filter elements to capture realistic degradation across the system (accounts for flow patterns, baffles, and localized wear).
- Sampling procedure: step‑by‑step methods for removing filter elements from dry-type dust collectors and replacing them with new elements.
- Sample preparation: methods for safely removing adhered dust prior to testing and for cutting specified test specimen sizes from the filter element.
- Measurement parameters: mandatory and optional tests including appearance inspection, photography, tensile strength, elongation, air permeability, and microscopic observation of fibres and damage.
- Sample handling, storage & transport: procedures to preserve sample integrity and protect health during handling and shipment.
- Reporting and analysis: required test report elements, and informative annexes such as fault tree analysis (FTA) for diagnosing filter media damage and example reports/results.
Practical applications and who uses it
ISO 22031:2021 is intended for practical use in industrial filtration and environmental compliance contexts:
- Filter system operators and maintenance teams - to monitor in-service filter degradation and plan replacements or maintenance.
- Testing laboratories - to ensure consistent specimen preparation and measurement that allow comparable degradation assessments.
- Filter manufacturers - to evaluate long‑term performance of filter media under real operating conditions.
- Plant engineers and environmental managers - to assess collection performance, residual pressure drop trends, and risk of dust leakage.
- Regulatory bodies and auditors - to verify that sampling and test methods meet recognized international practice.
By standardizing sampling locations, specimen sizes and test methods, ISO 22031 enables reproducible evaluation of filter life, fault diagnosis, and meaningful benchmarking across systems and vendors.
Related standards
- ISO 16891:2016 - test methods for evaluating degradation of cleanable filter media (referenced for tensile tests and related terminology).
- ISO 9237 - determination of permeability of fabrics to air (referenced for air‑permeability testing).