Selection criteria when choosing the optimal liquid filter bag
The following parameters and criteria are important in regards 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 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, a 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 contaminate 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 cartridges 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 less bag change-outs, longer on line filtration, reduction in overall cost