What is one function of a duplex filter in hydraulic systems?

A duplex filter in hydraulic systems primarily serves the function of allowing for flow alteration during maintenance without interrupting the operation of the system. This type of filter is typically designed with two parallel filter elements. While one filter is in service, the other can be taken offline for cleaning or replacement, ensuring that there is no loss of flow in the hydraulic system.

This capability is critical in maintaining uninterrupted operation in systems where hydraulic pressure and flow are essential to functionality. By utilizing a duplex filter, operators can perform maintenance tasks efficiently without causing downtime, which is often costly in hydraulic applications.

The other options do not accurately describe the primary function of a duplex filter. For instance, while a duplex filter does enhance filtering efficiency by providing the ability to switch between filter elements, its main distinguishing feature is the provision for maintenance without affecting system performance. Increasing hydraulic pressure is beyond the scope of a filter's function; filters are designed to separate contaminants from the fluid rather than modify pressure. Likewise, regulating thermal expansion is typically managed by other components in a hydraulic system, not by filters.