Fritted Ware Selection Guide Available Porosities Coloration Customized Products There are four different porosities of PYREX® brand fritted ware available, so that precipitates varying in size can be filtered at maximum speed with no sacrifice of retention. Porosity is controlled in manufacture, and discs are individually tested and graded into these classifications. The extra coarse and coarse porosities are held toward the maximum pore diameter as listed. The medium and fine are held toward the minimum pore diameter as listed. The porosity for the pore diameter of the filter is determined in the same manner as specified in ASTM E-128 "Maximum Pore Diameter and Permeability of Rigid Porous Filters for Laboratory Use." Also, where the size of the piece permits, it is marked with the ASTM designation followed by the pore range in microns as shown in the column Nominal Maximum Pore Size (microns).
| Porosity | Catalog
abbreviation | Nominal maxium
pore size
(microns) | Principal uses | | Extra coarse | E C | 170 to 220 | Filtration of very coarse materials. Gas dispersion, gas washing, extractor beds, support of other filter materials. | | Coarse | C | 40 to 60 | Filtration of coarse materials. Gas dispersion, gas washing, gas absorption. Mercury filtration. Extraction apparatus. | | Medium | M | 10 to 15 | Filtration of crystalline precipitates. Extraction apparatus. Removal of "floaters" from distilled water. | | Fine | F | 4 to 5.5 | Filtration of fine precipitates. Mercury valve.
Extraction apparatus. |
The "whiteness" of various fritted products may vary slightly from piece to piece due to minor color variations in the batch mix. This color variation does not affect product filtration performance nor is it frit contamination.
Special apparatus with fritted discs or tubes can be supplied to order. Call our Application Specialists at (800) 323-4340 for more information. |
