Selection criteria when choosing the optimal liquid filter bag
The following parameters and criteria are important in regard to the selection of the most suitable filter bag/cartridge for your application:
Selection Criteria Filtration Efficiency
Efficiency Comparison Chart
Within this Chart, we have provided details of a range of bags/Elements that all fit into standard P2 size vessels. It is important to not over filter as this will result in a shorter life. If existing nominal filtration is working and an absolute filter is still required then select the absolute filter by following the chart, eg PENG or PONG 1 micron filter bag equals an absolute 50 micron CHF element at 99% filtration efficiency.
On the other hand, Nominal micron ratings are average or general in nature. Their efficiencies can fall anywhere between 50% and 95% with the norm being around 80% efficiency. That is to say, one micron nominally rated filter bag will remove approximately 80% of “challenge particles” one micron or larger under
laboratory conditions. Eg PONG and PENG Bags
As the name suggests, absolute conjures up a notion of 100% pure filtration. Absolute rated filter bags are generally between 90% and 95% efficient with cartridges and membranes from 95% to 99.9% so contrary to their name, are not absolute (100%). They are generally gauged by the percentage of contaminated particles they are capable of removing in perfect laboratory conditions. For example, a 1 micron Absolute rated filter bag will remove between 95% and 98% of laboratory “challenge particles” 1 micron or larger. They are not 100% efficient. For this reason, we refer to this type of filter bag as “Absolute @95% efficiency” eg POMF filter Bags.
When 99% efficiency is required within a vessel you can now use CHF range of Elements, this combines the efficiencies of a filter cartridge with the benefits of a bag.
Selection Criteria Chemical Resistance
Performance of different filter bag materials
Filter Bags – Standard sizes
Filter Bags – Dirt Holding Capacity
A higher dirt loading capacity indicates longer service life, eg fewer bag change-outs, longer online filtration, reduction in overall cost