Pressure water treatment filter is a RSF contained under pressure in a steel tank, which may be vertical or horizontal, depending on the space available. Similar to gravity filters, the media in pressure filter is usually sand or a combination of media also called multimedia filters. Filtration rates are similar to gravity filters. The below figure shows the details of vertical and horizontal pressure water treatment filters.
These filters are commonly used for iron and manganese removal from groundwater, which is first aerated to oxidize the iron or manganese present, then pumped through the filter to remove the suspended material. Pressure filters are also used in swimming pool for recirculation water treatment.
Regardless of the method of control, the water filter eventually fills with suspended material. At some time, usually after 15 to 30 hours, it will need to be backwashed similar to rapid sand filter to clean the media and restore the normal rate of filtration.