Here is a guide for the selection of an appropriate filter to perform the efficient filtration.
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Select the filter with the filtration efficiency suitable for the particle size to be separated or collected from the fluid to be filtrated.
The filtration efficiency is expressed differently depending on the type of filter due to the filtration mechanism.
If the filter efficiency is the same, both the type and gexpressionh, it is possible to select a filter based on the specific filtration efficiency of the filter. If, however, the type and gexpressionh are not the same, it might be impossible to compare particle size to be collected by the filter and make a selection.
If there are anything unclear about the details of the filtration efficiency, please feel free to contact us.
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Filter type
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Ways of expressing filtration efficiency
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Analytical filter papers
Industrial filter papers
Glass fiber filter papers
Thimble filters
PTFE filters
Filter pads
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Nominal rating
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Non-woven filters
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Nominal rating
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Membrane filters
Disposal syringe filter units
37mm monitors
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Pore size
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Cartridge filters
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Pore size
Nominal rating
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Compact cartridge/Capsule filters
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Pore size
Nominal rating
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Ultra filters
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Molecular weight cut off
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k‚Ql
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Select the filter with the desired flow rate.
The flow rate increases with the rising of the differential pressure if the filtration area is the same, or it increases with the enlarging of the filtration area if the differential pressure is the same.
On the other hand, the flow rate decreases as the pore size goes down, or it decreases as the viscosity of the fluid rises.
In the event that the flow rate is lower than the required one, either raise the differential pressure or replace the filter with one that has a larger filtration area.
The disposable syringe filter units and the capsule filters have a specified maximum operating pressure, and the cartridge filters and the compact cartridge filters are specified the maximum operating differential pressure, therefore, do not use them past the those specified pressures.
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k‚Rl
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Select the filter with the desired filtration life.
The filtration life is greater with a larger filtration area.
If the filter becomes clogged with the suspended substances, the flow rate will decrease or the differential pressure will rise, causing the filter to reach the end of its life.
If the flow rate or the differential pressure reaches the specified control value, please change the filter promptly.
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k‚Sl
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Select the filter which has an appropriate resistance to the fluid to be filtered.
The resistance consists of gChemical resistanceh and gHeat resistanceh.
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If using a filter which has limited or no resistance to filtered chemicals, it will cause the filter to dissolve or swell.
The chemical resistance is different depending on the filtration conditions (temperature, concentration and time, etc.), therefore, an evaluation test before using the filter is recommended. Please also check the chemical resistance of the gasket(s) of the filter holder or housing in addition to this test.
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‡A
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The heat resistance is the maximum operating temperature the filter can be continuously used without a decrease in performances of the product. The maximum operating temperature is indicated for each type of filter.
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k‚Tl
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The major sterilization methods of the filters are autoclaving, in-line steam and ethylene oxide gas sterilizationsf, however, some types of filters are unable to be applied to these methods.
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k‚Ul
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Our company offers a wide range of filters, ranging from disposable filter units which are suitable for low-volume filtering to cartridge filters which are suitable for high-volume filtering.
After selecting a filter, please conduct a preliminary filtration test by using the desired fluid to check the performance and conditions of the filtration.
If the filtration life was not as expected, the particle consistency in the fluid might be too high.
In such case, using the pre-filter with a filtration efficiency lower than that of the selected filter will enable you to perform more efficient filtration.
Multiple pre-filters may be used, if necessary.
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