Duplex Automatic Housing Systems

Continuous, uninterrupted operation is provided by these automatic duplex filters

When the filter bags on one side get to the point of requiring change-out, the incoming flow is automatically diverted to the clean filter bags on the other side.

Maintenance personnel are alerted to the need to change the dirty filters so that the system will be ready for the next cycle.

Typical step-by-step operation

  1. As the filter bags in vessel A become so loaded with particulate that the differential pressure increases to a selected level, a switch actuates an air-operated valve in the loop pipe.
    This diverts a small flow of fluid to fill vessel B. After enough time to equalize the pressure in the two vessels, the four main valves are actuated by an air cylinder.
  2. The duplex valve system shifts four valves at once, closing the inlet and outlet on vessel A and opening the two on vessel B.
    An indicator light (and remote signal, if desired) shows that vessel B is now being utilized. Another light shows that the shift from one vessel to the other has occurred, and that filter bags need to be replaced, An electrical interlock prevents another shift cycle until the dirty filter bags have been replaced and the operator has pushed a reset button.
  3. With the interlock released, the system is ready to cycle whenever the pressure differential again indicates the necessity.


The automatic duplex valve system can be ordered on any Rosedale filter vessel. The standard multi-bag filter models are shown in the table.

The main inlet and outlet connections can be positioned to accommodate any flow direction within reason.

Systems are shipped assembled, ready for use, often on dollies or skids to assist putting them in place.

How to Order