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There are Six porosities available of Brand filter & dia from 10 mm to 150 mm sizes.
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| Grade Of Porosity | Average Dia of Fores in Micron | Main Uses |
| 0 | 150 to 200 | Gas distribution in liquids, very coarse Precipitation. |
| 1 | 90 to150 | Filtration of very coarse precipitates, coarse gas filters, Gas distribution liquids in large bubbles. Extraction of coarse grain materials, Foundation for adsorptive layers for filtering gelatinous precipitates. |
| 2 | 40 to 90 | Preparative work with Crystalline precipitates. |
| 3 | 15 to 40 | Preparative work with fine precipitates, Analytical work with medium precipitates, Fine gas Filters Gas distribution in liquids in fine bubbles, Extraction of fine grain materials. Mercury Filters. |
| 4 | 5 to 15 | Analytical work with fine and very fine precipitates preparative Filtration of finest precipitates, very fine gas distribution, in liquids under pressure, Non-return and stop value for Mercury. |
| 5 | 0.7 to 2.0 | Bacteriological Filtration, extremely fine gas distribution in liquids at higher pressure. |