They are medium efficiency filters composed of a series of pockets through which the air to be treated passes. These pockets are made in polyester fibers filtering media (self-extinguish according to DIN 53438) and are properly clamped to a support frame, available also in plastic material. Strong edge welds ensure the good seal of pockets. The property of these filters is the high filtering surface (proportional to the depth of the bags and their number).
The version with the support frame made of plastic, besides ensuring a perfect seal between the filter media and frame, facilitates the disposal of filters after their use (incinerable).

Applications

They are used either as final filters or as pre-filters for high efficiency filters in air treatment units and ventilation plants. Their high dirt storage capacity makes them suitable should high dust charge be present.

Features

Their self-supporting capability ensures them to bear any working discontinuity. In order to increase stability pockets with diamond separators are available on request.
They are available in 4 models: SP 15, SP 20, SP 40 and SP 55.
The efficiencies and filtration classes in accordance with EN ISO 16890 and EN 779 and the initial pressure drops at the rated flow rate for some standard formats available are:

The limit working temperature is of 90°C approx.
Capacities comprised between the 75% and the 125% of the mentioned ones are allowed for a good working of filters. Approximately it is possible to consider, inside this range, a linear correspondence between resistance and capacity.

Installation & service

They can be installed into proper holding frames having frontal access and usually designed to fit any possible pre-filters (suggested for SP 55 types).
It is advisable to replace these filters once having reached a resistance of 250÷300 Pa.