Overview
ISO 2194:1991 is an international standard developed by the International Organization for Standardization (ISO) that specifies the designation and nominal sizes of openings for industrial screens. These screens, which include woven wire cloth, perforated plates, and electroformed sheets, are essential components in industrial screening and sieving applications. The standard replaces the first edition from 1972, expanding its scope to cover more types of screening media and a wider range of sizes. ISO 2194:1991 ensures uniformity and clarity in the specification of screen openings, supporting streamlined procurement, manufacturing, and usage across global industries.
Key Topics
- Designation of Screen Openings: ISO 2194:1991 establishes a consistent method for designating the sizes of openings in woven wire cloth, perforated plate, and electroformed sheet. This includes referencing nominal aperture sizes and, where applicable, the type of weave or hole shape.
- Nominal Size Series: The standard adopts principal and supplementary size series:
- Millimetre Sizes (Table 1): Principal sizes (R10 series) range from 1 mm to 125 mm, with supplementary R20 and R40 sizes covering the same range.
- Micrometre Sizes (Table 2): Principal sizes (R10 series) from 5 μm to 800 μm; supplementary R20 from 20 μm to 900 μm, and R40 from 32 μm to 950 μm.
- Preferred Numbers: Aperture sizes are based on the R10, R20, and R40 series of preferred numbers, as specified in ISO 3 and ISO 497, which use geometric progressions for consistent scaling.
- Unit Expression: Openings of 1 mm and above are expressed in millimetres; those below 1 mm, in micrometres.
Applications
ISO 2194:1991 is widely used in industries requiring precise and reliable screening media, such as:
- Mining and Mineral Processing: For classifying bulk materials by size using robust industrial sieves.
- Food and Beverage Production: To ensure product quality through consistent particle sizing.
- Pharmaceutical Manufacturing: For separating and sizing powders and granules.
- Chemical Processing: Where accurate filtration and separation are critical for product purity.
- Environmental Engineering: In water treatment and waste management systems requiring effective screening of particulates.
- Research Laboratories: Supporting uniform test methodologies and repeatable results.
The standard simplifies communication between manufacturers, suppliers, and end users by providing a universal reference for opening sizes and screen designations.
Related Standards
ISO 2194:1991 aligns closely with several other international standards that address terminology, test methods, and preferred numbering:
- ISO 3:1973 - Preferred numbers - Series of preferred numbers (basis for the geometric progression in size series).
- ISO 497:1973 - Guide to the choice of series of preferred numbers and series containing more rounded values.
- ISO 9044:1990 - Technical requirements and testing for industrial woven wire cloth (references tolerances for aperture sizes).
- ISO 7806:1983 - Codification for designating perforations in industrial plate screens.
- ISO 9045:1990 - Vocabulary for industrial screens and screening.
By referencing these standards, ISO 2194:1991 supports a consistent, interoperable framework for the specification and use of industrial screening media worldwide.
Keywords: ISO 2194, industrial screens, woven wire cloth, perforated plate, electroformed sheet, nominal sizes, screen designation, millimetre sizes, micrometre sizes, sieving, screening, standardization.